Aside from an attack on Yemen in 2009, cluster munitions were not deployed by Washington since the Iraq invasion

Four Republican congressmen have asked US President Joe Biden to send cluster munitions, a controversial weapon banned in 110 countries, to Ukraine, dismissing concerns about escalating the conflict as misplaced in a letter to the White House on Tuesday.

The Biden administration shouldn't hesitate to send cluster munitions - specifically dual purpose improved conventional munitions (DPICM) - because of "vague concerns about the reaction of allies and partners and unfounded fears of 'escalation'," Sen. James Risch (R-Idaho), Sen. Roger Wicker (R-Mississippi), Rep. Michael McCaul (R-Texas), and Rep. Mike Rogers (R-Alabama) wrote in their letter. After all, they said, other countries have already sent such weapons without triggering Russian retaliation.

Acknowledging the weapons' horrific effects, the signatories argued that while Ukrainian leaders are "aware of the risks to non-combatants," the "existential threat posed by Russia's invasion and daily acts of barbarity" is more important. Additionally, they claimed, "d," US DPICM are equipped with "technologically advanced measures" that limit collateral damage.

A 2008 UN treaty banned cluster munitions in 110 countries, including three-quarters of NATO member nations. It has been signed by another 13 countries, though neither Russia, Ukraine, nor the US are on that list. Ukraine is the only country where the deadly devices are currently in use, and both sides have been accused of deploying them in the conflict.

Aside from one attack in Yemen in 2009, the US has not used cluster munitions since it invaded Iraq in 2003 and has not produced any since 2016. Central Command has admitted the hundreds of smaller bombs they contain are often left unexploded across the strike area, posing risks similar to landmines to anyone - especially children - who encounter the odd-looking little "petal mines."

While the White House initially balked at Kiev's request for DPICMs in December, it stopped short of a hard "no," and the issue is reportedly still under consideration if the US runs out of available ammunition to ship overseas. 

In April, 27 members of Congress denounced Russia's alleged use of cluster munitions, calling them "barbaric and indiscriminate weapons" and urging Biden to join the UN convention. The current policy, they said, was "wholly unacceptable given what we know about the immediate and long-term damage done to societies on which they are deployed."

While the Republican Party's 2022 campaign platform stressed curtailing the Biden administration's blank check to Kiev, the Pentagon announced another $350 million in weapons just this week, to be drawn from the US' own stockpiles.