As the conflict in Syria rivets international attention, Iran's nuclear program continues apace. Unfortunately, while the Iranians install the next generation of centrifuges — machines that can produce enriched uranium three to four times faster than before — the "P5-plus-1" negotiations on Iran's nuclear program have ground once again to a halt.

While economic pressures impose a cost on Iran, so far they have failed to alter its nuclear program. Ayatollah Ali Khamenei may acknowledge that sanctions are "brutal," but he also seems to feel that Iran has endured worse. In light of President Barack Obama's objective of preventing the Iranians from acquiring nuclear weapons, something has to give.

At a minimum, the supreme leader must be made to feel that when the United States says the time for diplomacy is running out, we mean it — and that the consequence is likely to be the use of force.