Poland’s Leader Suggests Russian Hand in Plot to Attack Western Cargo Planes

Poland’s prime minister appeared on Wednesday to confirm the conclusions of western intelligence officials who had warned of a Russian plot to blow up cargo aircraft over western countries.

“I can only confirm that Russia planned acts of air terror, not just against Poland but against airlines across the globe,” the prime minister, Donald Tusk, said during a meeting with Ukraine’s president, Volodymyr Zelensky.

Mr. Tusk did not elaborate, and it was unclear whether officials believed that Moscow was continuing to actively plan such an action.

Officials first became aware of the plot over the summer, when incendiary devices placed at shipping hubs in Britain and Germany ignited fires that caused minimal damage. In November, four Western officials briefed on intelligence about the operation said the fires had been part of a test of security measures carried out by Russia’s military intelligence service, known as the GRU.

The ultimate goal of the plot was not known, but intelligence agencies started an investigation into whether the intent was to destroy planes on American or European runways, or even blow up an aircraft midair.

By the fall, the White House became so concerned that President Biden ordered his national security adviser and the C.I.A. director to warn top aides of Russia’s president, Vladimir V. Putin, that such plotting could provoke a severe reaction from the United States. Any acts of sabotage that caused mass casualties would represent a serious escalation of conflict between Moscow and Washington, and the United States would hold Russia responsible for “enabling terrorism,” a senior official told The New York Times.