Lapsing military preparedness has led to disasters for nations time and time again. Alabama Republican Sen. Tommy Tuberville is playing a risky game for the United States’ armed forces by undermining preparedness, and he should stop.

Tuberville is holding up more than 270 promotions for top members of the military because he is not happy that the Pentagon pays for service members to go elsewhere if the state in which they are stationed will no longer allow abortions. It’s gotten to the point that the Marine Corps has no top leader for the first time in 164 years.

Historically, the Pentagon has paid for travel if service members or their dependents need specialized care, but the military does not pay for abortions. On Thursday, the House voted to overturn the Pentagon policy, which could make some Democrats leery of voting for the bill.

Tuberville’s antics might play well politically in Alabama, although the state’s women and many service members really ought to remember this when it is time to vote. But it’s important to recall that an important job of any military is to constantly prepare for serious challenges, which is harder to do if service members can’t move into key positions.

The world has no shortages of such challenges. The Ukraine war could spiral unpredictably. The situation between Taiwan and mainland China is unnerving. Who knows what our military could be called on to do in a hurry?

Leadership failures in the past have changed the course of history. The Persians weren’t ready for the Greeks’ phalanx strategy at the Battle of Marathon. King Philip II’s Spanish armada didn’t anticipate England’s naval tactics. France fell in less than six weeks to Germany’s unexpected blitzkrieg. Books such as Rick Atkinson’s “The Guns at Last Light” and David Ramsay’s and Edward E Gordon’s “Divided on D-Day” record how difficult it is to get things right in the fog of war, even with fully functioning military leadership.

The idea that a single senator, under arcane Senate rules, can upend U.S. military readiness is unconscionable. At a press conference on Thursday in Finland, President Joe Biden said it was up to Republican leaders to get Tuberville to back down. So far they haven’t.

If Tuberville won’t stop blocking military promotions, Congress should find a way to get the job done without him.

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