Campbell’s assessment seems to contradict those of the Pentagon and America’s allies in Europe.

At a meeting of countries that support Ukraine late last month, Secretary of Defense Lloyd Austin said that Russia had suffered more than 315,000 casualties during the war. With a drop in American aid, leading to ammunition shortages on Ukraine’s front lines, Russian forces have advanced. But those too have been costly, the Pentagon has said.

In an interview earlier this year, the chair of Lithuania’s national security committee estimated it would take Russia between five and seven years to reconstitute its forces for a full-scale war.