Little could show the need for congressional restraints more than President Donald Trump's weekend threat to attack 52 sites, including those of high cultural importance, if Iran attacks U.S. assets to avenge the killing of Gen. Qassem Soleimani.

How did Trump arrive at 52? In assembling his growing list of grievances, he reached all the way back to 1979, tying the number of sites to the number of American hostages taken during the Iranian revolution.

Let's just state plainly: It is absurd to tie any American foreign policy action to the events of more than 40 years ago. That does not diminish the importance of the hostage-taking at the time. But U.S. interests — and the deployment of the nation's might — should be driven by the here-and-now — not by a foolhardy attempt to resurrect outrage over long-past events.

Trump's reasoning, to the extent he has offered any, is the simplistic logic employed by rival gangs. "They're allowed to torture and maim our people … and blow up our people. And we're not allowed to touch their cultural site? It doesn't work that way," Trump told reporters on Air Force One. That is not the mature reasoning of a world power. Trump seems utterly unmindful that his threat would violate international law, hold this country up to worldwide scorn and badly weaken our ability to act as moral force for good.

The Geneva Conventions of 1949 specifically prohibit "any acts of hostility directed against the historic monuments, works of art or other places of worship which constitute the cultural or spiritual heritage of peoples," or "using such objects in support of the military effort," or making such sites "the object of reprisals." The Hague Convention enhanced protection of such sites in 1999, defining serious violations as war crimes, which could carry "individual criminal responsibility."

For civilized countries, there are rules, even in war. In a 2017 article, the International Committee of the Red Cross noted that attacks against cultural sites, historic monuments, works or art or archaeological sites "are so much more than the destruction of bricks, wood or mortar. Attacks against them are in essence attacks on our history, our dignity and our humanity."

Facing an international outcry over the president's threats, Defense Secretary Mark Esper acknowledged Monday that striking cultural sites with no military value would be a war crime. Let's hope he's never pressed to defy a direct order from his commander in order to uphold the law.

Meanwhile, House Speaker Nancy Pelosi is right to bring forward a vote on a war powers resolution this week that would limit Trump's ability to take military action. The resolution, she stated in a letter, would reassert long-established congressional oversight "by mandating that if no further congressional action is taken, the administration's military hostilities with regard to Iran cease within 30 days." Yes, Trump is the commander-in-chief, but cooler heads should prevail.

United Nations Secretary General Antonio Guterres has warned that fast-rising tensions could lead countries to make decisions with "unpredictable consequences and a profound risk of miscalculation." His message is a simple one that should be heeded: "Stop escalation. Exercise maximum restraint. Restart dialogue. Renew international cooperation," and avoid a new war.