When asked why the Saudis would suddenly, after five years of war, propose a nationwide cease-fire, Elana DeLozier, a research fellow at the Washington Institute for Near East Policy who studies Yemen, attributed it to the pandemic.

“Coronavirus is the answer,” she said. “Coronavirus has freaked out everyone in Yemen.”

She called the Saudi announcement “the biggest concession and the biggest confidence-building measure that the Saudis have given since the beginning of the war.”

And the Saudis appeared to be using it as a way to gauge the Houthis’ willingness to negotiate.

“It really is a test case,” she said.

That meant that the cease-fire’s immediate success will largely depend on compliance by the Houthis, whose leaders did not immediately respond to the Saudi announcement.

Their forces have been making gains against Saudi-backed Yemeni forces in recent months, which may make them hesitant to give concessions. But they could see benefits to engaging in a peace process, if they feel that it recognizes the power they have gained during the war.

Saudi officials said the Yemeni government, most of whose officials live in Riyadh at the kingdom’s expense, had agreed to the cease-fire as well, but no Yemeni officials were on a telephone conference call with journalists to announce the cease-fire.