Michael D'Antonio is the author of the book "Never Enough: Donald Trump and the Pursuit of Success" and co-author with Peter Eisner of "The Shadow President: The Truth About Mike Pence." The opinions expressed in this commentary are those of the author. View more opinion articles on CNN.

(CNN) Donald Trump resorted to extreme measures by ordering the killing of Iran's most revered military leader — something other presidents have had the opportunity to do and didn't. Iran has promised retaliation. When it comes, it's likely that Iraqis, Iranians and Americans will be killed. Whatever happens, I suspect that the President will take comfort in the fact that he was true to himself.

Michael D'Antonio

The fact that our impeached President is still in office, calling the shots and directing attacks that could kick off a war, is deeply unsettling. However, it is reality, and the logical outcome of Trump's leadership style. It is also proof of how he acts under pressure.

Three years into his presidency, we must recognize if not accept that the Trump Way often involves saying and doing things others will not. He plays with the scarier elements of human nature — aggression, tribalism, fearfulness and rage — and is not interested in calling on our higher instincts. Trump has shown little interest in the peace-making and alliance-building other presidents practiced with great benefit for America and the world.

Provoking a military crisis, perhaps even a war, would perfectly fit his long-held view that human beings are "vicious" and "life is a series of battles." On Friday, Trump justified Soleimani's killing by saying the Iranian was "plotting imminent and sinister attacks on American diplomats and military personnel, but we caught him in the act and terminated him." However the president offered no concrete evidence to back his claim and the timing of the lethal strike, which came at a moment of high stress for the beleaguered Trump, is suspicious to say the least.

Two factors may have played a role in Trump's decision to greenlight this risky operation. First, his impeachment just weeks ago must have made him feel more embattled than ever. One Democratic member of Congress, who spoke to me on background after the impeachment vote, told me that some of his congressional colleagues feared that impeachment would only cause Trump to become more reckless.