Neil Macfarquhar

President Vladimir Putin dismissed Thursday reports based on leaked legal documents that some of his close associates had shoveled around $2 billion through offshore accounts in the Caribbean.

The partial truce that Russia and the United States have thrashed out in Syria capped something of a foreign policy trifecta for President Vladimir V. Putin, with the Kremlin strong-arming itself into a pivotal role in the Middle East, Ukraine floundering and the European Union developing cracks like a badly glazed pot.

Wildcat strikes and protests by workers have cropped up as the Russian government has cut salaries and subsidies in response to plunging oil revenues.

The global collapse in oil prices is reordering economic relations around the world, but the change is particularly daunting for Russia, which relies on energy exports for 50 percent of its federal budget.

Leaders in both Moscow and Ankara said Wednesday that they wanted to avoid ratcheting up the tensions between their countries after Turkey shot down a Russian warplane along the Syrian border, but the Kremlin was still weighing its options.

Two big powers supporting different factions in the Syrian civil war clashed with each other Tuesday when Turkish fighter jets shot down a Russian warplane that Turkey said had strayed into its airspace.

Once united under the Qaida brand, the groups split over differing strategies in Syria. The Islamic State has since emerged as the most dynamic, popular force among radicalized Muslims who see bloodletting as the best way to advance an Islamist agenda.

The Russians said they were coordinating their military campaign with France in sharply ratcheting up attacks on Syrian territory, especially areas held by the Islamic State, the militant group that has asserted responsibility for destroying the Russian jetliner and for the spree of deadly attacks across Paris.

President Vladimir Putin of Russia called his counterpart, Bashar Assad of Syria, to Moscow for an unannounced visit to discuss their joint military campaign and a future political transition in Syria, the Kremlin announced Wednesday.

Russia and the United States signed an agreement Tuesday that regulates all aircraft and drone flights over Syria, the defense departments of both countries announced.

President Vladimir V. Putin used a visit Sunday by the German chancellor, Angela Merkel, to call for a return to normal relations with Europe, brushing aside the widespread boycott by Western leaders of the huge Victory Day parade on Red Square a day earlier.

A cease-fire and an overall compact to end the war in eastern Ukraine were announced here Thursday by the leaders of France, Germany, Russia and Ukraine after marathon overnight bargaining that threatened to derail the attempt. Even as the agreement was announced, it appeared fragile, with officials on all sides saying there was more work to be done.