Plunge in Oil Prices Threatens Russia’s Vast Spending on Ukraine War

President Trump spared Russia from the tariffs he had imposed on 180 other nations in a bid to reshape global trade. But that did not exempt the country from the ensuing economic havoc.

The price of oil, the lifeline of Russia’s economy and war machine, has fallen nearly 15 percent since Mr. Trump announced the tariffs on April 2, setting off fears of a global recession. This week, the U.S. president suspended many of the levies for 90 days. The damage to the global economic outlook, which drives oil prices, is likely to be more lasting.

If the oil slump continues, the Kremlin is likely to begin cutting spending as soon as this summer, analysts say, and the slashing could eventually hit the military.

This means that in the long run, Mr. Trump’s trade measures could inadvertently do more to damage Russia’s ability to fund its war against Ukraine than the West’s systematic imposition of the most comprehensive package of sanctions in modern history.

Before the current economic shock, President Vladimir V. Putin had been on a roll. He had regained momentum in the war and seemingly pulled Mr. Trump closer to his side on the conflict.

The Trump administration has opened a diplomatic and economic assault against European allies that have been steadfast supporters of Ukraine. And a decoupling of trade between the United States and China could weaken both nations, while opening opportunities for other powers like Russia, a situation that would bring Mr. Putin’s vision of a “multipolar world” closer to reality.