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Although media coverage of President Obama's unfolding nuclear policy has focused on its implications for the United States, it is no less important to understand its effects on America's friends and allies. The New START arms control treaty with Russia, the administration's nuclear posture review, the recent Washington nuclear security summit, and the uncertainty surrounding May's Nuclear Non-Proliferation Treaty review conference are all reverberating in capitals worldwide.

Bad as Obama's policies are for America, they are equally dangerous for friends who have relied for decades on the U.S. nuclear umbrella as a foundation of their own national security strategies. As Washington's capabilities decline and as it narrows the circumstances when it will use nuclear weapons, allies are asking hard questions about whether the U.S. nuclear umbrella will continue to provide the protection it has previously.

Many allies see clearly that our mutual global adversaries have no intention of reducing their own nuclear programs in imitation of Mr. Obama. Our friends accordingly feel increasingly insecure. If Washington will not continue to hold the nuclear umbrella that has provided strategic stability for so long, other countries will begin making divergent decisions about how to protect themselves, including, for some, the possibility of seeking their own nuclear weapons.

John R. Bolton, a former ambassador to the U.N., is a senior fellow at the American Enterprise Institute and a Fox News contributor. He is the author of "Surrender Is Not an Option: Defending America at the United Nations and Abroad" (Simon & Schuster, 2007). To continue reading his column in The Washington Times, click here.

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