If successful, the negotiations over Iran’s nuclear program could make the world a safer place. But we could be safer still if we re-examined our own nuclear program.

We still have a Cold War arsenal of 1,700 nuclear weapons assembled to deter the Soviet Union from a land invasion of Western Europe. The Soviets had a similar size arsenal to deter us from using our nuclear weapons, and the promise of mutually assured destruction may have prevented a third world war in the 20th century.

But in the 21st century, the risks are much different. There is no more Soviet Union, and although Russia is still heavily armed, it doesn’t pose the same type of threat.

Today, defense strategists say our greatest nuclear threat is from terrorists, non-state actors who have no homeland to defend and who are not deterred by an American nuclear arsenal.

Another danger is the worldwide environmental disaster that would result from even a limited nuclear war. According to a study by Physicians for Social Responsibility, a war between nuclear states like India and Pakistan could disrupt global climate enough to result in massive food shortages and famine, putting the lives of 2.3 billion people at risk.

As the world’s leading nuclear power, we compromise our ability to discourage smaller nations from acquiring nuclear weapons. Other risks include accidental detonation and theft of nuclear material, which are risks that grow the more weapons we have.

The time to reconsider our nuclear strategy is now, when our Cold War arsenal is coming to the end of its useful life. Replacing it could cost up to $1 trillion over the next decade, at a time the country is looking to cut defense spending after 10 years of war. We would be safer with fewer nuclear weapons and a national defense tailored to our needs. We would also be better positioned to halt nuclear proliferation. Iran’s weapons are not the only threat to our security – we should also be concerned about our own.