Since the mid-2000s Mr. Putin has made it a priority to strengthen economic, military and diplomatic ties with Venezuela. Moscow has sold more than $10 billion in weapons—assault rifles, jet fighters, tanks and missile systems—to Caracas. In 2008 Mr. Putin sent two Russian Tu-160 bombers on a training mission to Venezuela. The late dictator Hugo Chávez celebrated their arrival, declaring “Yankee hegemony is finished.”

In 2014 Russian defense minister Sergei Shoigu announced plans to put Russian military bases in Venezuela, Nicaragua and Cuba. Last December Venezuela and Russia again held joint training exercises.

In a June 2018 speech, then U.S. Southern Command Admiral Kurt Tiddwarned about Russia’s incursions. “It has deepened ties with allies that share the Kremlin’s increasingly authoritarian approach to governance and resentment of U.S. global leadership,” he said. “It has extended financial lifelines to keep its allies in Venezuela, Cuba, and Nicaragua afloat.”