“Outrage is not a policy,” said Strobe Talbott, who was deputy secretary of state under President Clinton and is now the president of the Brookings Institution. “Worry is not a policy. Indignation is not a policy. Even though outrage, worry and indignation are all appropriate in this situation, they shouldn’t be mistaken for policy and they shouldn’t be mistaken for strategy.”

For Washington, there are limited options for applying pressure. Senator John McCain, the presumptive Republican presidential nominee, wants to throw Russia out of the Group of 8 major powers. Such a move would effectively admit the failure of 17 years of bipartisan policy aimed at incorporating Russia into the international order.

Yet Washington’s menu of options pales by comparison to Moscow’s. Masha Lipman, an analyst at the Carnegie Moscow Center, said “there’s a lot more” that the United States needed from Russia than the other way around, citing efforts to secure old Soviet nuclear arms, support the war effort in Afghanistan and force Iran and North Korea to give up nuclear programs. “Hence Russia has all the leverage,” she said.

In forecasting Russia’s potential for causing headaches, most specialists look first to Ukraine, which wants to join NATO. The nightmare scenario circulating in recent days is an attempt by Moscow to claim the strategic Crimean peninsula to secure access to the Black Sea. Ukrainian lawmakers are investigating reports that Russia has been granting passports en masse to ethnic Russians living in Crimea, a tactic Moscow used in the Georgian breakaway republics of South Ossetia and Abkhazia to justify intervention to protect its citizens.

Arms sales, as Mr. Assad’s visit underscored, represent another way Russia could create problems. Israeli and Western governments have already been alarmed about reports that the first elements of the Russian-built S-300 antiaircraft missile system are now being delivered to Iran, which could use them to shoot down any American or Israeli planes that seek to bomb nuclear facilities should that ever be attempted.

While Mr. Rogozin expressed support for assisting NATO in the war in Afghanistan, other officials have warned darkly about cutting off ties with NATO. The two sides have already effectively suspended any military cooperation programs. But Russia could also revoke its decision in April to allow NATO to send nonlethal supplies overland through its territory en route to Afghanistan.

Russia could also turn up pressure on Kyrgyzstan to evict American forces that support operations in Afghanistan and could block any large-scale return to Uzbekistan, which expelled the Americans in 2005. “The argument would be, ‘Why help NATO?’ ” said Celeste A. Wallander, a Russia scholar at Georgetown’s School of Foreign Service.