The warning, buried in an obscure government report this summer, was unflinching.

The Defense Department’s vaunted network of research laboratories — whose scientists helped develop satellite communication, radar technology, and even the computer mouse — was in trouble.

The labs lost a significant share of their staff last year, largely in response to the Trump administration’s efforts to thin the federal workforce, the report found. Refilling critical positions was proving difficult due in part to President Donald Trump’s demand that new hires be screened for their loyalty to his goals. The report, issued by the Pentagon, pointed to “potentially grave consequences for the future of national defense.”

The turmoil inside scientific research has extended beyond the Pentagon. The Energy Department, a key hub of nuclear and quantum research, has lost more than 1,000 scientists and technical staff.…