American and European officials say their concern is based in part on a growing conviction that the war will not end any time soon.
For nine weeks, President Biden and the Western allies have emphasized the need to keep the war for Ukraine inside Ukraine. Now, the fear in Washington and European capitals is that the conflict may soon escalate into a wider war — spreading to neighboring states, to cyberspace and to NATO countries suddenly facing a Russian cutoff of gas. Over the long term, such an expansion could evolve into a more direct conflict between Washington and Moscow reminiscent of the Cold War, as each seeks to sap the other’s power. In the past three days, the American secretary of defense has called for an effort to degrade the capability of the Russian military so that it could not invade another country for years to come. The Russians have cut off gas shipments to Poland and Bulgaria, which joined the North Atlantic Treaty Organization after the collapse of the Soviet Union; Ursula von der Leyen, the president of the European Commission, immediately denounced the move as an “instrument of blackmail.” Explosions have rocked a disputed area of Moldova, a natural next target for the Russians, and gas depots and even a missile factory in Russia have mysteriously caught fire or come under direct attack from Ukrainian forces. And with increasing frequency, the Russians are reminding the world of the size and power of their nuclear arsenal, an unsubtle warning that if President Vladimir V. Putin’s conventional forces face any more humiliating losses, he has other options. American and European officials say they see no evidence the Russians are mobilizing their battlefield nuclear forces, but behind the scenes, the officials are already gaming out how they might react to a Russian nuclear test, or demonstration explosion, over the Black Sea or on Ukrainian territory. “Nobody wants to see this war escalate any more than it already has,” John Kirby, the Pentagon spokesman, said on Wednesday when asked about Russia’s nuclear threats. “Certainly nobody wants to see, or nobody should want to see, it escalate into the nuclear realm.” American and European officials say their fears are based in part on the growing conviction that the conflict could “go on for some time,” as Secretary of State Antony J. Blinken put it recently. Talk of a diplomatic resolution or even a cease-fire — attempted at various points by the leaders of France, Israel and Turkey, among others — has died out. Both Ukrainian and Russian forces are digging in for the long haul, focusing on what they expect will be an artillery war in the south and east of the country, where Russia has focused its forces after a humiliating retreat from Kyiv and other key cities. “Putin is not willing to back down, nor are the Ukrainians, so there is more blood to come,” said Robin Niblett, the director of Chatham House, a British think tank. At the same time, American and European determination to help Ukraine defeat the Russians has hardened, partly after the atrocities in Bucha and other towns occupied by the Russians became clear, with even Germany overcoming its initial objections and sending artillery and armored vehicles. Seth G. Jones, who directs the European Security Program at the Center for Strategic and International Studies in Washington, said on Wednesday that “the risk of a widening war is serious right now.
