To paraphrase Donald Rumsfeld, you go to war with the decisions you have made, not the decisions you wish you would have made with better hindsight.

I believe that those of us who advocated the war, whether inside or outside government, carry lifelong responsibility for that advocacy. You do not disburden yourself of that responsibility by changing your mind after the fact. What matters to posterity are the things you said and did at the hour of decision. You cannot revoke the irrevocable.

I still think President Bush did right to warn the world of an “axis of evil” in his 2002 State of the Union address, a speech to which I made some modest contributions. (I tell the story in a memoir, The Right Man.) Back then, it was controversial to claim that North Korea was proliferating weapons technologies to Iran and Syria, or that Shiite Iran armed and supplied Sunni Hamas. These things are now universally known. But the step from describing the problem to acting on it was large and inadequately considered.

Inside the Bush administration, we thought we were ready to remake Iraq for the better—but we were not. We were ignorant, arrogant, and unprepared, and we unleashed human suffering that did no good for anyone: not for Americans, not for Iraqis, not for the region. Almost two decades later, the damage to America’s standing in the world from the Iraq War has still not been repaired, let alone that war’s economic and human costs to the United States and the Middle East.

The idea of repeating such a war, only on a much bigger scale, without allies, without justification, and without any plan at all for what comes next staggers and terrifies the imagination.

Read: The Iraq War and the inevitability of ignorance

The Trump administration is very probably bluffing in its current menaces to Iran. President Trump dislikes foreign military interventions and has tried to withdraw American forces from Syria and Afghanistan. It seems unlikely that he would willingly launch a major war against a near-nuclear state of more than 80 million people. But bluffs do get called—and then the bluffer must rapidly make some hasty calculations. Wars of words can escalate into real wars, real fast.

If the goal of some inside the administration is to goad Iran into striking first—thus forcing Trump’s hand—that’s a ruse that risks igniting a conflict much bigger than the one with Iraq, and one even less likely to succeed.

In 2003, Vice President Dick Cheney’s now notorious promise, “We will, in fact, be greeted as liberators,” had solid basis in plausibility. Shiite Iraqis had risen in arms against Saddam Hussein’s regime after the Gulf War of 1990–91. By 2003, Iraqi Kurdistan was a more or less autonomous region, hostile to the regime. The Iraqi government was regionally isolated: friendless and feared. Its military and security forces were broken and unreliable.