Donald Trump’s inaugural address showed that he intends to do things differently and to do different things. The biggest changes could come in foreign policy. His address shunned the usual talk about American global leadership. It instead described an America impoverished from bearing the burden for others. Trump’s America will tend to its narrow interests first: “Every decision on trade, on taxes, on immigration (and) on foreign affairs will be made to benefit American workers and American families.”
We will soon see how Trump’s rhetoric translates into actual policies. Perhaps his deeds won’t match his words. Practical realities could lead him to choose policies similar to his predecessors’, even if he insists otherwise. But he could also fundamentally reset the direction of U.S. foreign policy. If so, critics on Capitol Hill will find it difficult to stop him.
Some of the reasons why are obvious. The Constitution grants presidents considerably more leeway to act overseas than at home. Presidents alone decide whom to negotiate with and about what. They can nullify treaties, repudiate longstanding commitments, and initiate or sever diplomatic relations. They can assert an independent war-making authority. And as the Iran nuclear deal showed, they can use executive agreements to circumvent the Senate’s treaty-making power.
Congress has reinforced the president’s constitutional advantages over the decades by passing hundreds of laws delegating authority to the White House and cloaking many executive branch activities in secrecy. Even where Congress seeks to limit its delegations, presidents and their lawyers usually find ample room to maneuver. So the Authorization for Use of Military Force passed in 2001 to sanction the fight against al-Qaeda now provides the legal basis for the fight against the Islamic State, which didn’t exist at the time and is al-Qaeda’s rival if not its enemy.
On top of the formal powers rooted in the Constitution and in law, presidents enjoy what Alexander Hamilton hailed in Federalist No. 70 as the inherent advantages of "decision, activity, secrecy, and dispatch." The power to initiate events can be the power to define them. Congress certainly can reverse many presidential decisions if it so desires. Doing so, however, requires passing laws. That typically means overriding a presidential veto, a prospect made all the more daunting when the president’s party controls both houses of Congress.
Trump’s leverage over Congress benefits from two other factors specific to him. One is his demonstrated willingness to double down rather than retreat in the face of criticism. Presidents frequently recalibrate when opposition to their policies mounts. They choose to conserve their political capital for other fights. But presidents willing to pay the political price for ignoring widespread public disapproval, as George W. Bush did with the surge in Iraq, often get their way.
Even more helpful to Trump in carrying the day is what he hopes to accomplish overseas. Discussions about executive-legislative battles over foreign policy generally assume Congress is reining in an activist president. James Madison’s belief that the power of the purse is “the most complete and effectual weapon with which any constitution can arm the immediate representatives of the people” reflects that assumption. And as the recent demise of the Trans-Pacific Partnership attests, Congress is at its most powerful when presidents need its consent to act abroad.
But much of Trump’s foreign policy agenda looks to be about doing less and not more. He’s questioning the value of American alliances and foreign commitments rather than looking to deepen or extend them. And Congress historically has found it difficult if not impossible to get presidents to embrace initiatives that don’t interest them. Barack Obama’s dismissal of congressional calls to do more in Syria is only the most recent example of this longstanding dynamic. In short, Congress is far better positioned to constrain than to compel.
None of this is to argue that Trump will always have his way on foreign policy. All presidents face institutional constraints. And all presidents decide that some battles with Congress aren’t worth fighting. However, if Trump does choose to give life to the vision he laid out in his inaugural address, his critics on Capitol Hill will be reminded just how powerful presidents can be.