A good rule of thumb for an outgoing administration should be to do no harm. Instead, the actions of Trump officials now threaten to deepen the world's worst humanitarian crisis.

Outgoing Secretary of State Mike Pompeo is reportedly close to classifying Yemen's Houthi rebel movement as a foreign terrorist organization. The label might be legally justifiable. Pompeo's main goal, however, is almost certainly to intensify pressure on the Houthis' backer Iran before a new, ostensibly more dovish U.S. administration takes office. While President-elect Joe Biden technically could remove the Houthis from the list, doing so would be nearly impossible politically.

The designation threatens to do far more harm than good. If it goes forward, aid groups working in Houthi-controlled areas — which encompass 70% of the population — would have to suspend their activities or risk financial sanctions and prosecution. The move could also deter already limited commercial shipping, insurance and trade with Yemen, hurting civilians throughout the country. Yemenis can ill afford any cutoff in aid: According to the United Nations, 1 in 6 are expected to be nearing famine by early next year, while virtually the entire country faces extreme food insecurity.

Sanctions would also likely derail struggling efforts to negotiate a cease-fire in Yemen. They would have little impact on Houthi leaders, who don't travel abroad or hold international assets. And there's little reason to think they would prompt the Houthis to cut ties to Iran.

President Donald Trump's administration should heed calls to hold off on the designation. If Pompeo proceeds regardless, Biden's advisers can and should issue their own assurances to aid workers, making clear that they appreciate the need to balance human rights considerations against the challenge of combating illicit activity. That might encourage some groups to continue their efforts under the assumption they won't face prosecution next year.

It is past time for the U.S. to stop backing the disastrous Saudi campaign in Yemen, as Biden has pledged. The U.S. should also lend its weight to stalled diplomatic efforts to reach a cease-fire.

In the meantime, more money would at least help mitigate any damage caused by an interruption in aid over the next two months. It would be far better, for the sake of ordinary Yemenis, to avoid such unnecessary suffering in the first place.

From an editorial on Bloomberg Opinion