The United States needs tens of thousands more ventilators in the coming weeks to handle the wave of covid-19 patients, and the question of which states and hospitals receive them — and can therefore save lives — comes down to this: Who will play God?

Will it be U.S. and foreign medical device makers, whose overwhelmed order books position them to determine which hospitals, states or nations will get the ventilators they need? In the United States, will it be the states, which have been thrust into what New York Gov. Andrew M. Cuomo (D) called an eBay-style bidding war against each other?

The best alternative would be the federal government, which could play a constructive role in equitably allocating a scarce, lifesaving commodity — but has so far abdicated that responsibility. In fact, according to Mr. Cuomo, the Federal Emergency Management Agency has been bidding for ventilators against the states, competing rather than coordinating with them.

Americans can ill-afford such dysfunction. According to the analytics company GlobalData, the United States needs an additional 75,000 ventilators to cope with the pandemic’s serial punches, in city after city and state after state, over the coming months. And the rest of the world will need at least another 800,000 ventilators. Even with a full-court press by medical device makers helped by the U.S. auto industry, some of which are pitching in to help accelerate production, it appears unlikely that adequate numbers of ventilators, which help people breathe when they cannot do so for themselves, will be available soon enough.

Mr. Cuomo has pleaded for FEMA to play the role of a purchasing agent for ventilators — “Buy everything, and then allocate by need to the states.” FEMA or another arm of the federal government, perhaps the Defense Logistics Agency, could also step in to manage the supply of respirator masks, gloves and other critical medical supplies.

The crisis is imminent in New York, but other states face similarly dire predicaments. Louisiana Gov. John Bel Edwards (D) said his state’s ventilator supply will not last out this week; it has procured fewer than 300 and needs at least 14,000, he said.

Without adequate numbers of ventilators, hospitals and doctors will face agonizing choices, guided by criteria that differ from state to state — a grim lottery that determines which patients will be given the assistance they need to draw breath. In Britain, where the ventilator shortage is also acute, a doctors’ union has proposed that younger, healthier patients get priority access to the devices ahead of the elderly and those with underlying illnesses. Under those guidelines, even a patient whose condition is improving may be removed from a ventilator in favor of another judged to have a better chance at survival.

The worldwide ventilator deficit represents a failure of foresight and planning. Assigning blame for that failure is less important than addressing it in the present. In the United States, the urgent priority is to manage the shortfall as rationally as possible. For now, the federal government is flat-footed, a spectator to an unspooling catastrophe.