Moscow ? Russia stunned the West on Tuesday by recognizing the independence claims of two Georgian breakaway regions, and U.S. warships plied the waters off of Georgia in a gambit the Kremlin saw as gunboat diplomacy.

The announcement by Russian President Dmitry Medvedev ignored the strong opposition of Europe and the United States, and signaled the Kremlin’s determination to shape its neighbors’ destinies even at the risk of closing its doors to the West.

“We are not afraid of anything, including the prospect of a Cold War,” Medvedev said hours after announcing the Kremlin’s decision and one day after Parliament had supported the recognition.

While the risk of a military clash with the West seemed remote, the lack of high-level public diplomacy between the White House and the Kremlin added to an uneasy sense here at least of an escalating crisis.

Medvedev also promised a Russian military response to a U.S. missile defense system in Europe. Washington says the system would counter threats from Iran and North Korea, but Russia says it is aimed at blunting Russian nuclear capability.

The Kremlin’s recognition of the breakaway regions of South Ossetia and Abkhazia suggested it was willing to risk nearly two decades of economic, political and diplomatic bonds with its Cold War antagonists.

Medvedev’s grim announcement, carried on national television, inspired jubilation on the streets of the rebel capitals. In the South Ossetian capital of Tskhinvali, a parade of cars bearing the South Ossetian and Russian flags blared their horns, women cried for joy and gunmen fired their weapons in the air.

The United States, surprised by the speed of the Russian response, threatened a veto in the U.N. Security Council should Russia ask for international recognition for the territories.

“Abkhazia and South Ossetia are a part of the internationally recognized borders of Georgia and it’s going to remain so,” Secretary of State Condoleezza Rice said. President Bush called the Russian move “irresponsible.”

Germany and France also criticized the decision, while the British Foreign Office said it did “nothing to improve the prospects of peace in the Caucasus.”

The Kremlin insists, despite some doubts in the West, that its invasion of Georgia was a spur-of-the-moment response to the Georgian military’s surprise crackdown on South Ossetia.

By contrast, Moscow has had weeks to weigh the consequences of recognizing the breakaway regions.

Beyond a handful of resolute U.S. foes, such as Cuba and Venezuela, few other nations seem likely to follow the Kremlin’s lead.

Still, the Kremlin recognition marked an initial step toward what could become a push for territorial expansion.