Itís one thing for President Donald Trump to demonize CNN and other reputable news outlets for doing their jobs and exposing his mistakes out of a desire to gin up his right-wing audiences back home. But itís another altogether for the American president to use his bully pulpit as the leader of the free world to all but invite authoritarians across the globe to declare open season on news reporters. His Twitter rant over the weekend captures perfectly how this presidentís thoughtless words can pose immediate harm and danger to those he targets. It was a deplorable display that should worry all Americans who value truth, free speech and the safety of journalists abroad.Trump indulged further in his usual badgering of CNN last week, declaring in a Twitter post that "FoxNews is MUCH more important in the United States than CNN," and that outside the United States, "CNN International is still a major source of (Fake) news," adding "they represent our Nation to the WORLD very poorly."CNN was quick to fire back that it was not the governmentís propaganda arm ó its mission was solely to report the news. But by then the damage had already been wrought; correspondents expressed fears about the safety of journalists in the field. Press groups have worried for months that Trumpís viral attacks on the media would encourage foreign leaders in the darkest corners of the globe to jail, further harass or subject journalists to violence. A day after Trumpís tweet, Egyptís Foreign Ministry took to Twitter to denounce Western coverage of a terrorist attack in Sinai. The dog whistle is being heard loud and clear by governments across the world: Donít like what you hear? Attack the messenger.For decades, U.S. presidents have used the moral authority of their office as a bulwark against tyranny across the globe. Their support for press freedom has been an invaluable instrument in promoting human rights and democracy, with both Americaís allies and enemies. Singling out an American media institution as a poor excuse of U.S. values only invites governments across the world to delegitimize their media outlets, too. This is no game for reporters already facing dangers in the field. And itís a terrible lesson to younger leaders in emerging nations of the role of the press in society.