Democratic leaders were way off base in issuing harsh, knee-jerk denunciations of President Trump’s airstrike that killed Iranian terrorism maestro Qassem Soleimani.

Immediately after a U.S. military strike such as this one, especially in highly volatile circumstances, American elected leaders should strive to present a united front to the world. If they can’t actively support the president, the opposition can certainly express concern and reserve the right to make harsher criticisms later without showing the sort of open, strident divisiveness that plays into enemy hands. They should probably wait for the smoke to clear before they noisily undermine the commander in chief.

This was once both common wisdom and common sense, and it remains a bedrock American value, very much consonant with the spirit of the maxim that “politics should stop at the water’s edge.” Nobody expects fawning obeisance or an absence of debate, but situations involving such great peril should require statesmanlike restraint, at least in public. There will be time aplenty later, if warranted, for further, fiercer criticism, and there is nothing stopping anyone with a line to the president from dressing him down in private.

Before reviewing what today’s Democrats are saying, it might help to recall how Republicans reacted when President Bill Clinton ordered a series of far less time-sensitive bombings in Iraq during the very week of his December 1998 impeachment.

The killing of Soleimani took advantage of a rare, extremely timely opportunity amid ongoing attacks by Soleimani against U.S. personnel. In contrast, Clinton’s bombings against Saddam Hussein’s suspected weapons facilities could have been launched anytime. They did not involve a one-time chance amid immediate threats. Clinton's bombing campaign had been in its planning stages since February of that year, in response to Saddam’s chronic interference with U.N. weapons inspectors.

Clinton conducted the bombings just as the House was debating impeachment, leading some Republicans to criticize his timing. But almost none of them openly undermined their commander in chief by blasting the substance of his decision. Leading Republican senators, ranging from hard-line conservative Jesse Helms to moderate John Warner, all openly supported Clinton’s bombing campaign, and a day later, the House voted 417-5 in favor of a resolution supporting U.S. forces in the region.

There was a time when this sort of response was virtually mandatory. In times of potential crisis, the United States must speak with one voice.

Against that long tradition, many of today’s Democrats erupted with highly inflammatory language, from which U.S. enemies will take verbal and even moral ammunition. Speaker Nancy Pelosi said Trump had engaged in “provocative and disproportionate actions.” Sen Tom Udall of New Mexico said, “President Trump is bringing our nation to the brink of an illegal war with Iran.” Sen. Chris Murphy of Connecticut played into Iranian propaganda by calling the killing an “assassination” that could have the effect of “knowingly setting off a potential massive regional war.” Sen. Ed Markey of Massachusetts also called it an “apparent assassination” that amounts to “a massive, deliberate, and dangerous escalation of conflict with Iran.”

And former Vice President Joe Biden, who ought to know the dangers of such rhetoric, said, "President Trump just tossed a stick of dynamite into a tinderbox … We could be on the brink of a major conflict across the Middle East.”

Memo to Biden: You are a candidate for president. Your words about international affairs matter. If you want to dampen an explosive situation, don’t use such incendiary language. For a former vice president to tell a murderous regime that the current president is recklessly starting a major conflict is only to encourage that regime to react violently. Biden’s words themselves are dynamite in a tinderbox and are thus inexcusable.

Maybe Trump’s decision will prove wise, or maybe it will prove tragic and misguided. But the Democrats’ highly politicized reactions, in reckless disregard of American diplomatic needs and interests, increase the chances that tragedy will result.