A new cold war? Why the United States and Russia can't seem to forget about the past.

• Author: Smith, Patricia
• Position: INTERNATIONAL

Three years ago, during a trip to Washington, Russia's then-President Dmitri Medvedev had lunch with President Obama at a burger joint in Arlington, Virginia. For two nations that had long squared off during the Cold War, it was a once-unthinkable display of camaraderie.

And it wasn't the only sign of a thaw during Obama's first term: The U.S. established a critical supply corridor through Russia for American troops in Afghanistan. A nuclear weapons reduction treaty was negotiated. And in 2011, Russia agreed not to use its United Nations Security Council veto to block a U.S.-led bombing campaign against Libya during that nation's Arab Spring revolt.

Then last year, Vladimir Putin returned to the Russian presidency and everything went downhill. The two sides have been at loggerheads over the civil war in Syria. In Russia, the government kicked American aid organizations out of the country, passed a law banning American adoptions of Russian children, and cracked down on nonviolent protests calling for greater Russian democracy--all moves that have angered the U.S.

An even bigger blow came in August, when Russia offered political asylum to Edward Snowden, the former National Security Agency contractor who leaked information about secret American surveillance programs and is wanted for espionage by U.S. authorities.

Now, most experts agree, U.S.-Russian relations are at a historic low since the collapse of the Soviet Union 22 years ago marked the end of the Cold War. Obama's goal of "resetting" relations with Russia now seems more elusive than ever.

"The deterioration in U.S.-Russian relations didn't just begin recently," says Clifford Gaddy, a Russia expert at the Brookings Institution. "It's been a progressive thing, and it continues a general downward slide."

President Obama expressed his frustration on The Tonight Show in August: "There have been times where they slip back into Cold War thinking and a Cold War mentality," he said of the Russians. "And what I consistently say to them, what I say to President Putin is, 'That's the past and we've got to think about the future.'"

From the KGB to the Kremlin

Some of the tensions stem from Russia's slide back toward authoritarianism--which seems deeply rooted in its history. For 350 years, the country was ruled by powerful czars. In 1917, the Russian Revolution ushered in seven decades of brutal Communist rule under the Soviet Union--America's Cold War foe (see Key Dates).

The years that followed the...