Next week, Donald Trump will travel to Brussels for the annual NATO meeting with 28 of his fellow North American and European leaders. Naturally, given that the North Atlantic Treaty Organization is a multilateral agreement signed long before he entered office, the president has spent the run up to the two-day affair trashing the alliance and sending threatening letters to fellow members suggesting he may pull out of the thing unless his ransom demands are met. Following his alleged behind-the-scenes comments at the G7 summit in Quebec that “NATO as bad as NAFTA,” the latter of which he’s described as one of worst deals of all time, The New York Times reports that the president has penned a series of letters to allies including Germany, Belgium, Norway, and Canada bashing them for supposedly failing to spend enough money on defense.

To German Chancellor Angela Merkel, Trump—or an aide who has a significantly better grasp on the English language—reportedly wrote: “As we discussed during your visit in April, there is growing frustration in the United States that some allies have not stepped up as promised. The United States continues to devote more resources to the defense of Europe when the Continent’s economy, including Germany’s, are doing well and security challenges abound. This is no longer sustainable for us.” The president claimed that the “growing frustration” is supposedly not “confined to our executive branch” but felt in Congress, as well. He added that Germany is not only at fault for (allegedly) refusing to shell out its fair share, but for being a bad influence on other nations, as well: “Continued German underspending on defense undermines the security of the alliance and provides validation for other allies that also do not plan to meet their military spending commitments, because others see you as a role model.” Per the Times, other countries received similar chiding, including the veiled threat that it will “become increasingly difficult to justify to American citizens why some countries do not share NATO’s collective security burden while American soldiers continue to sacrifice their lives overseas or come home gravely wounded.”

While Trump’s comments are nothing new—at last year’s summit, he used his speech in front of the alliance‘s new headquarters to trash members for supposedly not paying their “bills,” and separately called Germany “very bad” for selling so many cars in the U.S.—the president’s belligerent behavior on trade over the past several months has increasingly given the rest of the world cause to worry he’s willing to stab historical allies in the back at a moment’s notice: