Experts say the next logical step would be for Washington and Moscow to focus their attention on reducing short-range/tactical nuclear weapons.

Analysts say another example of better relations between Russia and the United States is that Moscow toughened its position on Iran. It cancelled the delivery to Tehran of S-300 anti-aircraft missiles, a deal dating back to 2007. Russia also voted in favor of a United Nations Security Council resolution imposing new, tougher sanctions on Tehran, although the text was apparently watered down by Russia and China.

Once again, retired Marine Corps General Anthony Zinni.

"The more we can get the Security Council to be united in how we handle Iran, the better it is," noted retired Marine Corps General Zinni. "And obviously, the two parties that we are most concerned with are Russia and China, showing Iran that there is international cooperation and an international sense of what their behavior should be. Getting Russia to participate in that is critically important. I would like to see China more cooperative in that sense too."

Looking ahead, many experts say Washington and Moscow should build on the progress made in 2010. Possible new arms control talks and Russia's application to become a member of the World Trade Organization are two key issues facing Washington and Moscow in the months ahead.