The Islamic Republic of Iran is determined to become the world's tenth nuclear power. It is defying its international obligations and resisting concerted diplomatic pressure to stop it from enriching uranium. It has flouted several UN Security Council resolutions directing it to suspend enrichment and has refused to fully explain its nuclear activities to the International Atomic Energy Agency. Even a successful military strike against Iran's nuclear facilities would delay Iran's program by only a few years, and it would almost certainly harden Tehran's determination to go nuclear. The ongoing political unrest in Iran could topple the regime, leading to fundamental changes in Tehran's foreign policy and ending its pursuit of nuclear weapons. But that is an outcome that cannot be assumed. If Iran's nuclear program continues to progress at its current rate, Tehran could have the nuclear material needed to build a bomb before U.S. President Barack Obama's current term in office expires.