Moscow's latest saber-rattling — flying long-range bomber patrols toward the U.S. and Britain, launching planes from its sole aircraft carrier, redeploying the Russian fleet to the Mediterranean, engaging in war games with China and several central Asian nations — doesn't mean the Cold War has returned. What it does signal is Russia's willingness, emboldened by the oil wealth once again flowing to the government, to begin reasserting its historic role as a strategic counterweight to Washington. And if it can't quite muster the heft to do that alone, Moscow is increasingly allying with other nations to challenge America's global hegemony.

Geopolitical rivalry long predates the United States and the Soviet Union, of course; it dates back to the days of the Roman Empire. And the revival of such competition between Washington and Moscow is no surprise given Russia's recovery from its weakened position in the 1990s, which saw its regional and global influence dramatically reduced. But an oil price of $70 a barrel oil has filled the Kremlin's coffers and allowed it to pump money into its military. And the increased spending comes on the heels of a series of moves by Washington that has upset Russia anew, ranging from NATO enlargement and proposed missile-defense sites in the Czech Republic and Poland, to the Iraq war. At least partly in response, Russia recently planted a titanium reproduction of its flag at the North Pole, test-fired a new ballistic missile supposedly capable of thwarting Washington's fledgling missile shield, and has blocked moves at the U.N. aimed at granting Kosovo formal independence from Russia's ally, Serbia.

"Russia is back," says Cliff Kupchan, a Russia expert at the Washington-based Eurasia Group, a political risk advisory and consulting firm. "The Russian elites have more spring in their step than at any time since my first visit there in 1981, and they've had enough of U.S. unilateralism."

Officially, Washington isn't peeved by Russia's latest moves. "Militaries around the world engage in a variety of different activities," White House spokesman Gordon Johndroe said in response to news that Russia's long-range bomber missions were resuming after a hiatus of 15 years. "It's not entirely surprising that the Russian Air Force, the Russian military, might engage in this kind of activity." Could it be seen as a security threat to the U.S.? "I don't think our military has those concerns about it," Johndroe said.

But there is a sense inside the U.S. government that relations with the Russians have suffered as a result of the Administration's preoccupations with its "global war on terror" and the conflict in Iraq. "The old saw is that Washington is a one-crisis town," says Ariel Cohen, a Russia expert with the conservative Heritage Foundation in Washington. Beyond that, Cohen says, the U.S. has long misconceived the nature of a post-Soviet Russia. "They thought that Russia would just be a larger, colder France, huffing and puffing but not really doing anything," Cohen says. "But instead, Russia has decided to flex its oil-fed muscle and to go a happy place from which its elites came from: the Cold War."

Kupchan believes the Russians have a reason to gripe: While President Vladimir Putin was the first world leader to call Bush following the 9/11 attacks and offer assistance, Russia got little in return for its support and cooperation in the campaign against al-Qaeda. "They believe they were the first in the door after 9/11, and they've got an empty bag to show for it," he says. "Most of the current European security architecture," he adds, is built "on Russian weakness," and Moscow has had enough.

One response has been to cozy up to China — a strategic rival during the Cold War — through the Shanghai Cooperation Organization, which recently held a war game in Russian involving 6,500 troops. The six-year old group, sometimes called a "club of dictators" — its members also include the authoritarian governments of former Soviet republics Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan — is seen by some in the U.S. government as a retooled Warsaw Pact that could serve to balance NATO. The SCO rejected Washington's request for observer status, while welcoming Iranian participation. The SCO "is an incipient counterweight" to the U.S. and NATO, Kupchan says. "If they spike it with Iran, you've got something ugly."