The Obama Administration is currently working with the international community to relieve Syrian President Bashar Al-Assad of his chemical weapons stockpile. Of course, there’s ample reason for pessimism. Even if American and Russian officials were to work in perfect harmony, fully ridding Assad of his entire arsenal in the middle of a civil war will be difficult, complicated, and likely impossible.

The Syrian crisis speaks to the broader challenge of containing anti-American regimes equipped with weapons of mass destruction. While America pursues all available diplomatic options for curbing these threats, we must also possess the military capabilities to protect the nation in case diplomacy fails.

The most effective military technology for combating the mounting WMD threat is missile defense. The United States must continue to support these systems to protect its homeland. America has been the world leader in missile defense for more than 30 years.The first major breakthrough came with the Patriot system, first used in the Persian Gulf War. The Patriot boasts over 2,500 successful tests. It’s used by over a dozen American allies, including several in the Middle East, whose leaders watch warily as the Iranian nuclear program moves forward. This is just one component of America’s missile defense infrastructure.

The alarming rate of Iran’s progress toward a nuclear bomb underscores how wrong the Obama administration was to abandon our allies and scrap the planned missile defense shield program for Eastern Europe in 2009. That system’s chief purpose was to deter the Iranian nuclear threat. Without it, the hardliners in Iran can still make plausible threats against America and its allies. North Korea’s nuclear arsenal presents an even more serious problem. Satellite images released in September reveal that the country might be close to bringing its Yongbyon plutonium production reactor back on line. The Defense Intelligence Agency has concluded that the country could already have a nuclear weapon small enough to fit atop a missile.

Meanwhile, the threat of terrorists exploiting the resources of a weak or chaotic government like Egypt’s is very real. These radical non-state actors need just a single bomb attached to a single missile to present a serious threat to the United States. And Assad can’t be taken as an honest broker. In the event that he does agree to hand over his chemical weapons, it is unlikely we can confirm that all will be in custody. Witness the near-endless discovery of additional WMD facilities in Libya after their WMD disarmament 2003—and that wasn’t in the middle of a civil war. The key lesson from the last decade is that preventing hostile actors from obtaining and using the world’s most destructive weapons isn’t always possible.

In a world where more and more of our enemies can access WMDs, keeping the United States and its allies safe from a cataclysmic attack demands greater ingenuity and vigilance. Missile defense systems can play a crucial role in efforts to combat these threats.

Michael James Barton served as the deputy director of Middle East policy at the Pentagon from 2006 through 2009 and is currently a director at ARTIS Research.