Ukraine’s Struggle for Independence in Russia’s Shadow
1991 – 2022
Ukraine’s Struggle for Independence in Russia’s Shadow

Ukraine has been dogged by corruption scandals, economic mismanagement, and Russian interference since it achieved independence in 1991. Russian threats have intensified as Ukraine's ties with the United States and Europe have improved in recent years.

1991
December 1, 1991
Ukraine Votes for Independence
A male campaign worker flashes a newspaper to a crowd.
A campaign worker speaks to a crowd at a campaign stand in Kyiv. Liu Heung Shing/AP Images

Amid the dissolution of the Soviet Union, Ukraine votes for independence in a referendum, with 92 percent of Ukrainians supporting independence, and elects Leonid Kravchuk as president. Ukraine had the second-largest population and economy of the fifteen Soviet republics.

1991
1994
January 14, 1994
Securing Nuclear Warheads
A ballistic SS-19 missile is seen hanging from a crane while soldiers look on.
Soldiers prepare to destroy a ballistic SS-19 missile at the former rocket base in Vakulenchuk, west of Kyiv. AP Images

The Russian, Ukrainian, and U.S. presidents sign a statement that reaffirms Ukraine’s commitment to transfer all strategic nuclear warheads to Russia and dismantle strategic launchers in its territory. The statement also confirms Russian readiness to compensate Ukraine for the value of the highly enriched uranium in the warheads, notes U.S. readiness to assist Ukraine in dismantling the launchers, and specifies security assurances Ukraine will receive once it accedes to the Nuclear Nonproliferation Treaty (NPT) as a non–nuclear weapons state.

1994
1994
February 8, 1994
Ukraine Joins NATO’s Partnership for Peace
Six Ukrainian UN peacekeepers with blue berets laugh.
Ukrainian UN peacekeepers in the northern Serbian town of Novi Sad in 1994. NATO had conducted air strikes in the region. Ivan Milutinovic/Reuters

The North Atlantic Treaty Organization (NATO) welcomes Ukraine into its Partnership for Peace, a collaborative arrangement open to all non-NATO European countries and post-Soviet states. Ukraine and Hungary become the fifth and sixth members of the partnership. Russia becomes a member that June and conducts various cooperative activities with NATO, including joint military exercises, until 2014, when NATO formally suspends ties. As the Cold War ended, Russia had opposed the eastern expansion of NATO. However, thirteen former partnership members eventually join the alliance.

1994
1994
July 10, 1994
Kuchma Becomes President
Photo showing Ukrainian president Leonid Kuchman raising his joined hands in front of his face.
Ukrainian President Leonid Kuchma visits Athens, Greece, in November 1994. Viktor Korotayev/Reuters

Former Prime Minister Leonid Kuchma defeats incumbent President Leonid Kravchuk. It is the first time an incumbent has been defeated in a presidential election in a former Soviet republic. Kuchma’s presidency is marked by slow growth, several economic crises, and charges of rampant corruption.

1994
1994
December 5, 1994
Budapest Memorandum Signed
Photo showing Russian President Boris Yeltsin, U.S. President Bill Clinton, Ukrainian President Leonid Kuchma, and British Prime Minister John Major, during the signing of the Budapest Memorandum.
Russian President Boris Yeltsin, U.S. President Bill Clinton, Ukrainian President Leonid Kuchma, and British Prime Minister John Major, during the signing of the Budapest Memorandum. Win McNamee/Reuters

The Budapest Memorandum on Security Assurances [PDF] is signed by Russia, Ukraine, the United Kingdom (UK), and the United States, following Ukraine’s accession to the NPT as a non–nuclear weapons state. Russia, the UK, and the United States commit to respecting Ukraine’s sovereignty, territorial integrity, and independence, and promise to not threaten or use force against Ukraine.

1994
1996
June 28, 1996
New Constitution Ratified

The Ukrainian parliament ratifies a new constitution [DOC]. It theoretically requires separation of powers, but the president holds significant sway. He or she can dismiss the prime minister and rescind acts of the cabinet, for instance. Among other things, the constitution guarantees free speech and private-property ownership and recognizes Ukrainian as the sole state language.

1996
1997
July 9, 1997
NATO, Ukraine Deepen Partnership
Ukrainian President Leonid Kuchma exchanges documents with NATO Secretary-General Javier Solana after a signing ceremony during the NATO summit.
Ukrainian President Leonid Kuchma exchanges documents with NATO Secretary-General Javier Solana after a signing ceremony during the NATO summit. Blake Sell/Reuters

Kuchma meets with NATO leaders in Madrid, where they sign a document establishing a distinctive partnership between Ukraine and the defense alliance. Under this partnership, a NATO-Ukraine commission will meet at least twice per year to discuss the relationship.

1997
2000
September 2000 – November 2000
Gongadze Scandal Prompts Protests
An angry woman shouts and waves a paper with the portrait of opposition journalist Georgi Gongadze, as she takes part in a protest
An angry protester waves a poster of missing opposition journalist Heorhiy Gongadze during a rally calling for Kuchma’s resignation in Kyiv, Ukraine, in December 2000. Gleb Garanich/Reuters

On September 16, Heorhiy Gongadze, a Ukrainian journalist investigating alleged corruption in the Kuchma administration, disappears. His beheaded body is found two months later in a forest outside of Kyiv. Audio recordings eventually surface that purport to show Kuchma ordering subordinates to kill Gongadze. The scandal spurs public discontent about corruption among Ukraine’s elites, leading to street protests. Western countries reconsider their support of Kuchma’s government.

2000
2001
April 2001
Prime Minister Yushchenko Ousted Amid Reform Moves
Prime Minister Viktor Yushchenko, surrounded by deputies, wipes away a tear.
Outgoing Prime Minister Viktor Yushchenko, surrounded by deputies, prepares to address a crowd of supporters. Mikhail Chernichkin/Reuters

The parliament passes a no-confidence motion against Prime Minister Viktor Yushchenko, who steps down. The vote is carried out by parties allied with Kuchma, who had surprised observers when he nominated Yushchenko to be prime minister in 1999. Yushchenko and his deputy Yulia Tymoshenko had been pushing through energy sector reforms that became unpopular with many of Kuchma’s oligarch supporters.

2001
2004
November 2004 – December 2004
Orange Revolution Overturns Flawed Election
A line of police officers facing a crow of protesters with banners and Ukrainian flags.
Police guard the parliament building in Kyiv as it is surrounded by opposition supporters. Sergey Supinski/AFP/Getty Images

The 2004 presidential race pits Western-oriented Yushchenko against Viktor Yanukovych. Yanukovych is Kuchma’s preferred choice and the candidate supported by Moscow. The election is a tug-of-war between those who seek closer ties with the European Union (EU), NATO, and the West and those who favor closer alignment with Russia. Yushchenko mysteriously suffers dioxin poisoning in September; he survives but with his face disfigured. After two flawed rounds of voting award the election to Yanukovych, protesters dressed in orange, Yushchenko’s campaign color, take to the streets in large numbers and force a revote in December, which Yushchenko wins. The second so-called color revolution in a post-Soviet state—a year after Georgia’s Rose Revolution—sets off alarm bells in Moscow.

2004
2006
January 2006
Russia Shuts Off Gas
A man operates a wheel from a pipeline.
A Ukrainian operator at the main pipeline in the village of Boyarka, near Kyiv. Ivan Chernichkin/Reuters

A pricing and transit dispute between the Yushchenko government and Russia’s state-owned Gazprom results in a gas cutoff, lasting a couple of days and quickly causing supply drops in European countries that import Russian gas via Ukraine. The dispute underscores the energy interdependence between Russia and Ukraine, with 80 percent of Russia’s gas exports to Europe passing through the country. At the same time, Ukraine relies on Russia for much of its own natural gas supply, for which it has historically paid below-market rates. The shutdown occurs amid an economic slowdown that begins to dent Yushchenko’s popularity.

2006
2008
April 3, 2008
NATO Expansion Bid Meets Opposition
Russian President Vladimir Putin holds up both index fingers while speaking into microphone.
Russian President Vladimir Putin speaks after the NATO-Russia Council meeting at the 2008 Bucharest summit. Natalia Kolesnikova/AFP/Getty Images

NATO begins its twenty-second summit amid a debate about whether it should offer Membership Action Plans (MAPs)—forerunners to membership—to Croatia, Georgia, and Ukraine. But in discussions between NATO officials and Russian President Vladimir Putin, Putin expresses opposition to extending MAPs to Georgia and Ukraine. Unable to reach a consensus, NATO members decline to offer a MAP to either. During a separate meeting, Putin reportedly tells U.S. President George W. Bush that Ukraine is “not even a real nation-state.”

2008
2008
August 2008
Russia Invades Georgia
Russian armored vehicles advance outside of Gori
Russian armored vehicles advance outside of Gori, Georgia. Gleb Garanich/Reuters

Russian troops invade Georgia following a Georgian military operation against a South Ossetian separatist stronghold. The invasion leads to a five-day war and results in an increased Russian presence in the breakaway Georgian republics of Abkhazia and South Ossetia, which represent roughly one-fifth of Georgian territory. Yushchenko sides with Georgia, further increasing tensions between Kyiv and Moscow. Russia subsequently recognizes both republics as independent states, though neither is recognized as an independent state by most countries.

2008
2008
September 2008
Talks Open on New EU Relationship
 President Jose-Manuel Barroso, French President Nicolas Sarkozy, and Ukrainian President Viktor Yushchenko shake hands and smile.
European Commission President Jose-Manuel Barroso, French President Nicolas Sarkozy, and Ukrainian President Viktor Yushchenko greet before an EU-Ukraine summit in Paris. Charles Platiau/Reuters

The EU and Ukraine begin talks on a new “association agreement” and issue a communiqué that “Ukraine’s future is in Europe.” The EU considers such agreements to be legally binding contracts that commit countries to developing closer political, legal, and trading ties with the EU and sometimes lead to accession to the bloc. Implementation of the association agreement could mean major changes in Ukraine that would bring it closer to EU standards.

2008
2010
February 7, 2010
Yanukovych Elected President
Viktor Yanukovich waves with both hands to his supporters during a rally in Kyiv.
Viktor Yanukovich greets his supporters during a rally in Kyiv. Sergei Supinsky/AFP/Getty Images

Yanukovych narrowly defeats Tymoshenko, prime minister at the time, in a presidential election that most international observers view as free and fair. Aided by political consultants from the United States, Yanukovych recasts himself as more open to EU integration. His victory is a sign of voter disillusionment with Tymoshenko and Yushchenko after several years of economic trouble.

2010
2011
May 2011 – December 2011
Tymoshenko Sentenced, Brussels Freezes Agreement
Former Prime Minister Yulia Tymoshenko is seen outside the court surrounded by microphones from journalists.
Former Prime Minister Yulia Tymoshenko outside of court. Sergei Svetlitsky/AFP/Getty Images

Yanukovych has Tymoshenko arrested for “abuse of office,” and she is sentenced to seven years in prison. International observers see the prosecution as a politically motivated way for Yanukovych to sideline his main opponent, and the U.S. ambassador calls the trial a farce, a view shared by many. The jailing stalls negotiations with the European Union over improving trade and political ties. Brussels refuses to finalize the association agreement at the December EU-Ukraine summit in Kyiv.

2011
2013
November 21, 2013
Yanukovych Withdraws From EU Talks
President Viktor Yanukovich winks at Russian President Vladimir Putin during a meeting in Moscow.
President Viktor Yanukovich and Russian President Vladimir Putin during a meeting in Moscow. Sergei Karpukhin/Reuters

The Ukrainian government states that it will not sign the association agreement at an upcoming EU-Ukraine summit in Lithuania. Yanukovych’s administration announces it will resume dialogue with Russia about joining the Eurasian Customs Union. Protests begin in Kyiv almost immediately.

2013
20132014
November 2013 – February 2014
Euromaidan Protests Lead to Government Collapse
 A protester waves the Ukrainian flag from the top of a statue during clashes with riot police in Independence Square in Kyiv.
An anti-government protester waves the national flag from the top of a statue during clashes with riot police in Independence Square in Kyiv. Reuters

Ukrainians turn out in large numbers to protest Yanukovych’s announcement on EU ties. Mostly peaceful demonstrations continue for two months in Kyiv’s main Maidan square. They turn violent after the government moves to break up protesters, and the ensuing crackdown kills more than one hundred people. On February 21, Yanukovych and opposition leaders reach a settlement that includes plans for presidential elections before the end of the year. Soon after, Yanukovych flees to Russia. He leaves behind a lavishly decorated palace, which protesters see as evidence of his corruption. Ukraine’s acting president and acting prime minister make it clear that a top priority will be to bring Ukraine closer to Europe.

20132014
2014
February 2014 – March 2014
Russia Seizes Crimea, Holds Referendum
A man passes by a campaign poster in Crimea comparing Ukrainian control to Nazism and urges voters to choose to join Russia instead.
A campaign poster in Crimea compares Ukrainian control to Nazism and urges voters to choose to join Russia instead. Viktor Drachev/AFP/Getty Images

Pro-Russia forces, including so-called little green men—Russian soldiers in Russian uniforms, but with identifying insignia removed—seize control of Crimea, a Ukrainian peninsula where the majority of residents are ethnically Russian. Soon after, authorities hold a disputed referendum in which Crimean voters choose to secede and join Russia. Brussels calls the referendum “illegal and illegitimate,” and Washington promises it will never be accepted. Russia annexes Crimea on March 21, though the UN General Assembly votes 100–11 against recognizing the referendum result and Russia is expelled from the Group of Eight. A month later, Putin admits that Russian soldiers were involved in the annexation and justifies it as a way to protect ethnic Russians allegedly threatened by violence from Kyiv.

2014
2014
April 2014
Russia Backs Bloody Separatist War
Pro-Russia activists raise the flag of the so-called Donetsk People’s Republic.
Pro-Russia activists raise the flag of the so-called Donetsk People’s Republic. Alexander Khudoteply/AFP/Getty Images

Russia provokes an armed separatist movement to seize government buildings across eastern Ukraine’s Donbas region. Ukrainian forces resist but are wary of sparking a much wider war, with Russian troop buildups reported along the border. By early 2022, fighting has resulted in more than fourteen thousand deaths, a quarter of them civilians, and two million internally displaced Ukrainians. Parts of two regions—Donetsk and Luhansk—declare themselves independent republics.

2014
2014
May 25, 2014
Poroshenko Elected President
Presidential candidate Petro Poroshenko stands in front of poster displaying other presidential candidate's election results
Presidential candidate Petro Poroshenko on election night. Sergei Supinsky/AFP/Getty Images

Petro Poroshenko, a pro-West oligarch, wins an outright majority in the first round of Ukraine’s presidential election, surprising many. Poroshenko promises to fix the economy by aligning Ukraine with Europe and to root out corruption that has trailed Ukraine since its independence. U.S. President Barack Obama’s administration signals interest in helping Poroshenko battle corruption and assigns Vice President Joe Biden as its chief envoy for Ukraine.

2014
2014
July 17, 2014
Passenger Jet Shot Down With Russian Missile
Debris from Malaysia Airlines Flight 17 burns in a field in eastern Ukraine.
Debris from Malaysia Airlines Flight 17 burns in a field in eastern Ukraine. Pierre Crom/Getty Images

A Malaysia Airlines flight from Amsterdam to Kuala Lumpur is shot down by a surface-to-air missile over eastern Ukrainian territory controlled by Russian and Russian proxy forces, resulting in the death of all 298 people onboard. A Dutch-led investigation later finds that Russia bears responsibility, with the missile having been provided by a Russian army brigade, but Russia denies responsibility.

2014
2014
September 5, 2014
First Minsk Agreement Signed
Two men watch a column of Ukrainian tanks as they roll through the streets.
A column of Ukrainian tanks rolls through the Donetsk region in September 2014. Anatolii Stepanov/AFP/Getty Images

Russian units enter Ukraine to push back Ukrainian forces that were on the verge of regaining control of Donbas. Shortly after, negotiators conclude the first Minsk Agreement, aimed at ending the fighting. However, its terms are not implemented, and fighting continues along the line of contact.

2014
2015
February 11 – 12, 2015
Second Minsk Agreement Signed
German Chancellor Angela Merkel hugs French President Francois Hollande after peace talks in Minsk.
German Chancellor Angela Merkel and French President Francois Hollande after peace talks in Minsk. Grigory Dukor/Reuters

Putin and Poroshenko meet in Minsk to negotiate a cease-fire in eastern Ukraine. They reach an agreement, shepherded by French President Francois Hollande and German Chancellor Angela Merkel, that outlines thirteen steps to end the war, including an immediate cease-fire and the withdrawal of all heavy weaponry in order to create a “security zone.” Fighting and shelling along the line of contact still flare up from time to time. Both sides trade accusations on violations of the deal, though international observers place more blame on Russian and Russian proxy forces.

2015
2017
December 2017
Lethal U.S. Arms Sales Allowed
A Ukrainian soldier displays a Javelin anti-tank missile during a military parade.
A Ukrainian soldier displays a Javelin anti-tank missile during a military parade. Gleb Garanich/Reuters

Under President Donald J. Trump, the United States approves lethal arms sales to Ukraine, moving beyond the nonlethal military assistance that the Obama administration had allowed. That summer, Trump had named Kurt Volker as his special envoy for Ukraine negotiations. Prior to that, the U.S. Congress created the Ukraine Security Assistance Initiative, which authorized hundreds of millions of dollars in additional military aid for Ukraine.

2017
2019
January 2019
Schism Emerges in Orthodox Church
Ecumenical Patriarch Bartholomew and Metropolitan Epifaniy, head of the Orthodox Church of Ukraine, attend a ceremony marking the Ukrainian Orthodox Church’s independence.
Ecumenical Patriarch Bartholomew and Metropolitan Epifaniy, head of the Orthodox Church of Ukraine, attend a ceremony marking the Ukrainian Orthodox Church’s independence. Murad Sezer/Reuters

The Ecumenical Patriarch of Constantinople, the leading authority for Orthodox Christianity, recognizes the independence of the Ukrainian Orthodox Church, formally severing it from the Russian Orthodox Church, which has close reported ties to the Kremlin and had overseen the Ukrainian church for centuries. Russia accuses the United States of encouraging the break in order to weaken Moscow, and a Kremlin spokesperson reissues a promise to defend “the interests of Russians and Russian-speakers.”

2019
2019
April 21, 2019
Volodymyr Zelensky Elected
Volodymyr Zelensky surrounded by supporters claps his hands as he celebrates the announcement of the first exit poll at his campaign headquarters.
Volodymyr Zelensky celebrates following the announcement of the first exit poll at his campaign headquarters. Valentyn Ogirenko/Reuters

Volodymyr Zelensky, a television comedian and political novice, wins a presidential runoff with more than 70 percent of the vote, defeating Poroshenko. Two months later, Zelensky’s party also wins a majority of parliamentary seats, marking the first time since independence that Ukraine’s president has a majority party in the parliament. Zelensky had campaigned against corruption and poverty, and pledged to end the war in the east; many saw the vote as a rejection of Poroshenko and his failure to root out corruption.

2019
2019
July 25, 2019
A Phone Call Reverberates
Ukrainian President Volodymyr Zelensky listens during a bilateral meeting with U.S. President Donald J. Trump on the sidelines of the UN General Assembly.
Ukrainian President Volodymyr Zelensky listens during a bilateral meeting with U.S. President Donald J. Trump on the sidelines of the UN General Assembly. Jonathan Ernst/Reuters

Trump and Zelensky have a phone conversation that later becomes the focus of an impeachment inquiry by the U.S. Congress into abuse of power and obstruction of justice. A U.S. government whistleblower expresses concern about Trump’s alleged effort during the call to enlist Zelensky to investigate Biden, a leading Democratic candidate in the 2020 presidential election. In November, several former and current U.S. officials testify before lawmakers that the Trump administration postponed a Trump-Zelensky meeting and held up congressionally approved military assistance to get Kyiv to investigate Biden. White House officials dismiss the complaints as politically motivated, and in January 2020 Trump is acquitted in a Senate vote mostly along party lines.

2019
2020
June 2020
Making a Deeper Commitment to NATO
President Zelensky meets with NATO Secretary-General Jens Stoltenberg in Brussels.
President Zelensky meets with NATO Secretary-General Jens Stoltenberg in Brussels. John Thys/AFP/Getty Images

Ukraine is named a NATO Enhanced Opportunities Partner in June, joining Australia, Georgia, Finland, Jordan, and Sweden as countries with deeper cooperation on NATO-led missions and exercises. The alliance says the new status “does not prejudge any decisions on NATO membership.” In September, Zelensky approves Ukraine’s new National Security Strategy, which provides for the development of a distinctive partnership with NATO with the aim of gaining membership. The previous year, Zelensky’s predecessor signed a constitutional amendment committing Ukraine to become a member of NATO and the EU.

2020
2021
February 2021
Zelensky Cracks Down on Pro-Moscow Oligarchs
Viktor Medvedchuk appears before a Kyiv appeals court.
Viktor Medvedchuk appears before a Kyiv appeals court. Anna Marchenko/TASS/Getty Images

Zelensky orders a series of measures against oligarchs, notably Viktor Medvedchuk, a businessman, chairman of Ukraine’s largest pro-Russia political party, and close friend of Putin’s. The government freezes his financial assets for three years and shuts down three pro-Russia TV channels that Medvedchuk controls, alleging that they broadcast “misinformation.” That May, authorities lodge treason charges against Medvedchuk, claiming that he transferred oil and gas production licenses in Crimea to Russian authorities. Zelensky says the moves are necessary to defend the country, while Putin blasts them as motivated by anti-Russia bias.

2021
2021
April 2021
Russian Military Buildup Raises Alarms
Russian troops participate in drills
Russian troops participate in drills at a military airdrome in Taganrog. Reuters

Officials from Ukraine and EU member states warn about recent Russian deployments near Ukrainian border areas and in Crimea. Adding up to more than a hundred thousand troops, along with tanks, rocket launchers and other weaponry, analysts call it the largest troop buildup since Russia’s 2014 annexation of Crimea. Biden, now U.S. president, and Putin agree to a June summit to discuss a range of contentious issues, including Ukraine, and launch dialogues on strategic stability and cybersecurity. The following month, Putin publishes an article titled “On the Historical Unity of Russians and Ukrainians,” in which he questions the legitimacy of Ukraine’s borders, asserts that Russians and Ukrainians are “one people,” and blames the collapse in bilateral ties on foreign plots and anti-Russia conspiracies.

2021
2021
September 2021
Nord Stream 2 Pipeline Completed
View of NordStream 2 pipeline
The Nord Stream 2 pipeline starts in Russia’s Leningrad Oblast. Peter Kovalev/TASS/Getty Images

The Russian energy firm Gazprom finishes construction of the Nord Stream 2, a pipeline that is set to deliver natural gas under the Baltic Sea to Germany and could cut off a major source of income for Ukraine, a current transit country. Leaders in Kyiv protest that Moscow will use the pipeline, which could double gas deliveries to the rest of Europe, as a geopolitical weapon. The Biden administration opposes the pipeline but agrees to hold off on sanctions and reaches a deal with Germany to fund alternative energy projects for Ukraine. Amid the Russian military buildup near Ukraine, Germany says a German-based firm involved in the project must take administrative steps before any gas can flow, a process that could take until mid-2022.

2021
20212022
December 2021 – January 2022
Russia Demands Security Concessions
A satellite image shows tanks and other military equipment in the Russian town of Yelnya, about 160 miles from the Ukraine border, in January 2022.
A satellite image shows tanks and other military equipment in the Russian town of Yelnya, about 160 miles from the Ukraine border, in January 2022. Maxar Technologies/Reuters

As Russia continues to mobilize tens of thousands of troops along the border with Ukraine, the Putin government demands a set of security guarantees from the United States and NATO. This includes a draft treaty calling for tight restrictions on U.S. and NATO political and military activities, notably a ban on NATO expansion. The Biden administration delivers written responses in January; few details are made public, but it rejects Russia’s insistence that Ukraine never be accepted into NATO and proposes new parameters for security in the region.

20212022
2022
February 2022
Russia Invades Ukraine
Two people watch as smoke rises on buildings from Russian airstrike in Lviv, Ukraine
People watch as smoke rises after a Russian airstrike hits Lviv, Ukraine, on March 26, 2022. Pavlo Palamarchuk/Reuters

Russia launches a multi-pronged assault on Ukraine, including an invasion by Russian forces from neighboring Belarus. In a series of addresses to the nation, Putin reiterates his claim that Ukraine is part of Russia and calls the government in Kyiv a fascist “puppet regime” run by foreign powers. He frames his intervention as a mission to “demilitarize” and “de-Nazify” the country and protect its Russian-speaking population in the east from genocide. Putin warns outside countries not to intervene, threatening them with “consequences you have never faced in your history.” The invasion draws broad international condemnation, including from the United States, European Union, and the United Nations, and Washington and Brussels promise “severe” sanctions on Russia. However, Biden rules out any involvement of U.S. troops in Ukraine. 

2022