(CNN) -- A year ago, U.S. President Barack Obama pledged to work for the elimination of nuclear weapons and within months he got the Nobel Peace Prize. This week, the world is getting some results.
The U.S. president met his Russian counterpart, Dmitry Medvedev, in Prague Thursday, to sign a new Strategic Arms Reduction Treaty. It will cut the number of long-range warheads deployed by the world's two largest nuclear powers by roughly a third, to 1,550.
The document is important, but it's the legacy of an arms race that's essentially over. Washington isn't worrying much about the men in the Kremlin any more; it believes the real threats come from North Korea, Iran and the caves along the Afghan-Pakistan border.
So it's taking other steps with those threats in mind:
• The Obama administration released a new policy statement known as the Nuclear Posture Review, ending development of new weapons and limiting how the U.S. would use the ones it has. Obama is scaling back, pledging that Washington won't use nuclear weapons against any nation that abides by the nuclear Non-Proliferation Treaty. Translation: if Iran and North Korea honor the treaty, Obama says they needn't fear American nukes.
• Next week, Obama will convene an unprecedented Global Nuclear Security Summit with more than 40 heads of state, to find new ways to keep nuclear materials out of the hands of threatening leaders, terrorists and arms traffickers. Once again, Iran and North Korea are likely to come-up in the conversation.
• Next month, the United Nations will host a global conference to review the Nuclear Non-Proliferation Treaty. That's the overriding global agreement to slow the spread of nuclear weapons and establish rules for the peaceful use of nuclear technology. The treaty gets an update every five years, but there are still big loopholes that, depending on your point of view, allow current nuclear powers to keep their weapons and emerging powers to acquire weapons of their own.
It's complicated stuff and the truth is that there are probably not a lot of votes in it for the president of country with a weak economy and stubborn unemployment.
But if you were wondering whether Obama really deserved the world's most prestigious prize for furthering the cause of peace, this is the time to watch closely.