David KriegerPresident Trump has demonstrated yet again why he lacks the understanding, intelligence and temperament to be president of the United States. By violating the Iran nuclear deal, he is undermining the security of the U.S., our allies and the world. There are many good reasons that the U.S. should have remained in the agreement, but Trump exploded those when he took the U.S out of the agreement.

First, the U.S. withdrawal makes it more likely that Iran will return to pursuing a nuclear weapons program. Given Trump’s threats, this will increase the possibility of a war with Iran, which would be costly in blood and treasure.

Second, it will be detrimental to U.S. relations with allies UK, France and Germany, all of which tried to dissuade the U.S. from withdrawing. Further, it will be detrimental to U.S. relations with Russia and China, which are also parties to the agreement. Under Trump, the U.S. is isolating itself and diminishing its leadership role in world affairs.

Third, it demonstrates that U.S. commitments are not to be relied upon. This will make it harder for other nations to trust the U.S. to keep its word. This may be a problem for the prospects for peace on the Korean Peninsula.

What lies behind Trump’s decision to leave the Iran deal? Again, there are different possibilities. One possibility is his seeming desire to reverse whatever Barack Obama achieved. In Trump logic, Obama’s legacy is to be reversed, regardless of the costs of doing so. Another possibility is that Trump is playing to his base, those who support U.S. arrogance in international relations regardless of the costs involved. Yet another possibility is that Trump wants to have a reason to go to war with Iran, and to use this as an excuse to solidify his power in the U.S. in the same way that Hitler did with the Reichstag fire.

Trump is literally playing with fire – nuclear fire – whether he understands it or not. He just made a very dangerous and ill-considered move on the chessboard of international affairs. But now, instead of having General H. R. McMaster, a relatively steady and sane person at the helm of the National Security Council, he has John Bolton, a cheerleader for regime change and a man who never met a war he didn’t like. In March 2018, Bolton published an opinion piece in The New York Times with the title, “To Stop Iran’s Bomb, Bomb Iran,” monumentally dangerous advice.

America, beware. Trump has just fired another serious warning shot across the bow of democracy, one that bodes ill for the nuclear non-proliferation regime, for peace and for the future of our democratic institutions. Once again, Trump has shown clearly that he is not fit to be president, and his impeachment should be undertaken as a matter of urgency.

David Krieger is a founder of the Nuclear Age Peace Foundation and has served as its president since 1982.