While premiums for Obamacare plans rose sharply for many customers this year, a growing body of evidence suggests that the insurers still in the market have begun making money and would be likely to stay if not for the administrative uncertainty. So far, there has not been a widespread run for the exits among insurers, but that could change if the companies feel that the administration wishes to actively undermine the markets.

President Trump, for the moment, appears to be leaning toward that course of action. In a Tuesday morning tweet, he wrote, “Let Obamacare fail and then come together and do a great healthcare plan.” Later in the day, he told reporters that Republicans should “let Obamacare fail,” adding, “I’m not going to own it.”

Republicans control both houses of Congress and the White House. But they have demonstrated that there is not enough agreement within the party to pass a major health overhaul bill. Mr. Trump’s argument is that catastrophe in the insurance markets will be enough to bring Democrats to the negotiating table. That could be a risky strategy.

There is, of course, another possible path. The Trump administration could take actions to reassure insurers and help stabilize markets. It could promise to fund the special subsidies, at least until the end of this year. It could signal that it will instruct the I.R.S. to continue enforcing tax penalties for Americans who lack health insurance. It could promise to advertise Obamacare’s fall sign-up period, increasing the number of Americans who learn about the program and get coverage. It could reach out to carriers and insurance commissioners to help them find ways to remain in bare markets.

It has the power to minimize damage from any of the current health law’s flaws. At the moment, that does not appear to be the chosen path.