President Trump should stop tweeting. Now.

Presidents have long been able to reach vast audiences by radio, television and, more recently, the Internet. But Donald Trump is the first one to insist on the ability to reach a global audience directly, unfiltered by aides, using his Twitter account. He boasts that social media allows him to bypass a news industry he claims to despise. It also allows him to bypass his own aides and a civil service skeptical of many of his policies.

Trump has thus far used social media to disrupt a centuries-old institution: the U.S. government. This is not a positive development — not even for Trump. In the long run, he will find that unfiltered tweeting will make it harder for him to accomplish anything. Other governments and his own officials alike will soon learn to discount rash statements that are not followed up by action or even lasting presidential attention. That will weaken U.S. influence abroad and degrade democratic oversight of foreign policy.

There’s long been a comfortable myth that presidents make foreign policy. We even name major foreign policies after the presidents who pronounce them: the Truman Doctrine, the Carter Doctrine and so on. In reality, those policies were rarely made by one person, and presidents only somewhat more often took a leading role. Most of the time, policy is designed by much larger groups of officials in a complex process of negotiation within the government.

Those processes can take months or years. They thwart presidents’ desire for rapid action and make it harder for policy to respond to new developments. But they also result in policies that are broadly acceptable, easily understood and able to be defended by administration spokespeople and diplomats.

Thanks to Trump’s tweet-fromthe-hip style, though, the romantic myth of a president making foreign policy has become reality. And it turns out things are not better this way. Trump’s choice of Twitter to announce his support for a Saudi-led coalition against Qatar, the host of a base critical to U.S. operations against the Islamic State, suggests that his announcement wasn’t driven by a careful, informed, interagency policy process.

The Qatar incident provides just one example of how Trump’s tweets short-circuit institutions designed to ensure that U.S. policy is made deliberatively and communicated effectively.

As the past six months have shown, the results are alternately baffling and horrifying. No spokesperson would have approved tweets critical of London’s mayor, Sadiq Khan. The National Security Council and State Department would have killed his tweet bashing Germany for not paying enough for NATO. And we are still trying to figure out what his tweets on China and North Korea (“China is trying hard!”) actually mean.

The whole point of institutions is to help systematize inputs and outputs to manage and understand a complex world. Wiring foreign policy to run through a single person begs for disaster — even more so when that person had no relevant experience before Jan. 20.

For now, the Qatar tweets appear to be the only ones that had a direct policy impact. Most tweets prove embarrassing but seem to have little effect on formal government decisions. Some might argue that’s good. No responsible government can change its foreign policy in 140 characters. And maybe it is healthier for the putative “adults in the room,” like H.R. McMaster and Jim Mattis, to quietly deep-six the president’s tweets and substitute a policy that works better. Yet democracy isn’t supposed to work by the expectation that appointed officials will engage in routine insubordination.

The likeliest outcome for the medium term is more of the same. The White House insists that the president’s tweets are presidential statements; the bureaucracy tries to clean up the messes as best as possible. That just ratifies the obvious: that the president has enough power to cause problems but not enough to impose his will on the government, let alone negotiating partners.

In the long term, the picture is grimmer. Ambiguity over who speaks for U.S. foreign policy and which presidential statements matter can only make it harder for other countries to ascertain what the United States will or won’t do.

All of these problems could be solved easily. Trump could impose some message discipline on himself and on his administration with relative ease. Giving up his iPhone, I stress, would be better for him. Rationing his words would make them more valuable and make it easier for aides to ensure his policies were being carried out.

But it’s unlikely that he will do so. (Indeed, he might dismiss this column as just another attempt by the “FAKE MSM” to get him to give up his Twitter.) In the meantime, Americans — and the rest of the world — wait to see which statements matter and which end up as covfefe.