Millions of people post messages on social media that are, for the most part, meaningless and egotistical, but overall, harmless.

But, when the leader of the free world cuts loose 140 characters, the effects could change the course of history.

Sure, most of Donald Trump’s messages are braggadocious and petty, from calling opponents cruel nicknames to exaggerating the size of the crowd at his inauguration, but his string of tweets last week set into motion a series of events that could rock his administration and, potentially, the world.

Of course, we’re talking about Trump’s early morning claim that Barack Obama wiretapped Trump Tower during the campaign. Without any evidence, Trump claimed he was the victim of McCarthyism and some illegal operation worse that Watergate.

Trump conflated McCarthyism’s witch hunt for communists and Nixon’s cover-up of a breaking in at the Democratic Party, but also drew attention to the suspicious connection between people involved in his campaign and some sort of organized hacking operation connected to Russians, whether government or mafia related.

Trump’s shocking claim that his predecessor abused the power of the presidency to help his preferred successor could have brought criminal charges if proven to be true. The claim immediately raised concerns because no one had previously claimed Obama had engaged in any illegally activity throughout his eight years in office.

The new president’s outrageous claim seemed so definitive that many thought it must have come as a result of Trump’s new access to the country’s investigative agencies and intelligence gathering capabilities.

But, just as quickly as the claims came, they seemed to fall flat when intelligence officials, former Obama officials, and even some high-ranking Republicans denied that any such covert operations occurred during the campaign.

In trying to defend the claims, White House officials cited published reports in right-wing media outlets as proof of the wiretapping. By this week, even Trump himself said he used the term “wiretapping” as a general description of surveillance that could have occurred during and since the campaign as the FBI investigated interference with the election by hackers, including Russian operatives. Trump didn’t have the courage to walk back his comments; instead, as usual, he doubled-down on another bald-faced lie.

It now seems clear that Trump exaggerated his claims based on conspiracy theories pushed by fringe political commentators. Those stories were loosely based on anonymous sources that have leaked information about on-going surveillance of Russian operatives that seem to have inadvertently snared some close advisors to Trump who had been communicating with Russians for either business or political purposes.

Trump’s tweets may have ended up drawing more attention to these investigations and raised even more suspicions about whether any of Trump’s associates were involved with or encouraged the hacking of Democratic Party emails that eventually helped Trump win the presidency. His own tweets may come back to rock his White House.

But, more importantly, Trump’s tweeting habits about both inane subjects, as well as divisive comments about China, Mexico, and North Korea, for example, diminish his standing, both at home and abroad.

The President of the United States is the most influential person in the world (in recent months, however, many have argued Vladimir Putin now claims that distinction), so every word he says can affect trade negotiations, political stability in foreign countries, even the overall level of security Americans feel about their own futures.

Every time Donald Trump jumps on Twitter and makes silly, baseless, and demeaning statements, it’s not just his own credibility that slips; America’s standing in the world diminishes when world leaders can’t take our president seriously. And based on Trump’s public and online comments, world leaders have reason to doubt the honestly, integrity, and intellect of our president.

The world is an increasingly unsafe place, with terrorists and despots jockeying for position in Syria, Iran, North Korea, and even Russia. Cyber security for businesses and government is a growing concern. Domestic economic and health issues leave millions of Americans worrying about their families’ well-being.

These would seem to be the important topics that should occupy our president day and night. We went through a grueling, divisive, and exhausting campaign cycle to elect our leader; now it’s time for the winner of that election to do the job he so desperately wanted. We need a Commander-in-Chief, a statesman, a leader we can feel confident is working to keep us safe and to improve our lives.

So far, Donald Trump seems more interested in petty social media games, more like what teenagers engage in, than in the serious work of being the President of the United States.

President Trump should be working day and night, as he promised during the campaign he would, to deal with the many important issues that should be on his desk. That would make us all feel more confident that he’s serious in protecting us, and make our enemies less likely to harm us.

It’s time to put that phone down, Mr. President.