Sometimes, as the leader of a global superpower, you very much want to coerce the behavior of another government, only to find your tedious public is not enthusiastic about the prospect of military intervention, probably because of the seven or so wars you're already fighting. A quandary!

Luckily for you, sanctions are a politically viable option instead. Especially when targeted at specific industries, state agencies, or officials, sanctions are cast as a shrewd and humane alternative to open conflict. We can make life difficult for corrupt politicians or halt oil sales or limit military build-up without hurting ordinary people, who likely have little control over their leaders' choices. All the coercion, none of the humanitarian consequences.

It sounds good in theory. It sounds clean and altruistic, foreign policy without the bloodshed. And though it's obviously true that sanctions do not mete out the direct damage of airstrikes or invasion, they are not the humanitarian alternative they're often made out to be. Even targeted sanctions can have grave unintended consequences for innocent civilians, as present circumstances in Iran and Venezuela reveal.

Drenched in heavy rains and spring snow melt, Iran is flooding. The country has suffered three major floods in the past two weeks, with 23 of 31 provinces affected as of this writing. Hundreds of villages and several cities are submerged. "In [the provincial capital city of] Khorramabad the water has risen by as much as three meters in parts," state media reported Monday, and some areas are "completely submerged with residents stranded on their rooftops." Tens of thousands of people have been displaced, and dozens have died.

The death toll could well grow, partly because international aid has been limited. "Two weeks into devastating floods that have caused tremendous losses and damages across Iran, there is still no report about other countries extending help," reports Radio Farda, a Persian-language subsidiary of the U.S.-funded Radio Free Europe/Radio Liberty. To all appearances, "European states as well as Iran's neighbors, particularly the wealthy Persian Gulf states, have also not made any official offers of help," the story says, some Turkish charities excepted.

More help is not forthcoming, the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) said, because "challenges caused by unilateral sanctions will affect the U.N. response and the accountability of the U.N. to deliver the appropriate support." The unilateral sanctions in question are those imposed by the Trump administration following President Trump's decision to withdraw the United States from the Joint Comprehensive Plan of Action (JCPOA), commonly known as the Iran nuclear deal.

In a tweeted statement, Iran's foreign minister, Javad Zarif, made the same charge more bluntly: Trump's sanctions are "impeding aid efforts by #IranianRedCrescent to all communities devastated by unprecedented floods," he said, an account the Red Crescent has confirmed, specifically pointing to limitations on Iranian access to the SWIFT banking system, through which the charity was previously transferring aid money to Iran. (Secretary of State Mike Pompeo on Tuesday said support could be directed to Iran's Red Crescent through the International Federation of Red Cross and Red Crescent Societies, but it is not clear how the transfer would happen in practice.) Zarif also claimed rescue helicopters are unable to reach flooding victims because sanctions have left Tehran's fleet in disrepair.

Half a world away, U.S. sanctions on Venezuela are indirectly worsening the chronic food shortages that are already starving Venezuelan children to death. "Though the United States was not responsible for the collapse of Venezuela's economy — that was a pure product of Hugo Chávez's potted version of socialism — the sanctions it imposed on Venezuelan oil in late January could compound the humanitarian crisis," explains The Washington Post's Jackson Diehl. Oil exports are Venezuela's "only significant source of hard currency," so as U.S. sanctions push export levels down, "Venezuelan imports of food and medicine, already disastrously insufficient, will drop off a cliff."

Removing these sanctions wouldn't magically restore Venezuela to abundance and stability — but neither will imposing them. Historically, sanctions have a pretty poor record of effectiveness. One study of 85 sanctions systems published in International Security identified just four successes. Sanctions are "not likely to achieve major foreign policy goals," the survey concluded, but they reliably "inflict significant human costs on the populations of target states, including on innocent civilians who have little influence on their government's behavior."

U.S. sanctions on Iran never forced Tehran to democratize, but they did prove deadly for Iranian innocents long before this spring's floods. And in Venezuela, President Nicolás Maduro has used U.S. pressure as propaganda to shore up his own power, depicting himself as a bulwark against the "imperialist" "gringos." What if the sanctions "plan doesn't work? Suppose the [Maduro] government holds on, and then you've duplicated the suffering and you haven't solved the problem," Crisis Group analyst Phil Gunson, who is based in Caracas, told the Miami Herald. "The prospect that it can be apocalyptic but not produce an outcome can be quite scary."

Sanctioning Venezuela's nationalized oil industry, which supports the Maduro regime, or limiting Iran's access to international financial institutions to discourage nuclear weapons development may sound like straightforward ways to coerce bad actors in these two countries without harming civilians. But the reality of sanctions isn't that simple. They're often unintentionally inhumane and rarely effective.

Sanctions may be a lesser evil than war, but that does not mean they cannot be cruel.