Yesterday, with much fanfare, Saudi Arabia proclaimed a ceasefire in Yemen and called for all-party talks to resolve the political crisis that has turned  the country into a failed state.

How, just hours after that announcement, Arab warplanes struck the city of Taiz while government-backed militias swear they won't stop fighting the Houthis.

New York Times:

The warplanes bombed Houthi positions during heavy clashes in Taiz on Wednesday morning, according to a local official in the city. The new airstrikes, combined with reports of continued fighting in other parts of the country, including the southern port city of Aden, dampened hopes that the Saudi announcement would quickly result in a broader cease-fire.

Saudi officials said on Tuesday that they were stopping the aerial operation because it had achieved its objectives, including destroying heavy weapons and missiles belonging to Yemeni troops allied with the Houthis. They had faced intensifying international pressure to stop airstrikes that were killing a growing number of civilians.

The United Arab Emirates have also carried out airstrikes as part of the campaign, and the United States has contributed logistical and intelligence support. But one of the principal Saudi goals remained unfulfilled: the restoration to power of the exiled Yemeni president, Abdu Rabbu Mansour Hadi, who was driven from power by the Houthis.

On Tuesday, the Saudis said they retained the right to “counter any military moves by the Houthis or their allies,” a possible signal that they intended to continue their military intervention by other means, like financing proxy troops.

The name of the Saudi operation was also changed, to “Renewal of Hope” from “Decisive Storm.”

There was little evidence of change in the nature of the combat on Wednesday. In several areas of Taiz, fierce clashes erupted between the Houthis and their allies, on one side, and militiamen loyal to Mr. Hadi on the other, according to Mohamed al-Haj, a member of the local council.

The Houthi forces continued their advance, trying to capture a military brigade that declared its loyalty to Mr. Hadi. The warplanes struck the Houthis in the morning. “There are many deaths on both sides,” Mr. Haj said.

It's an open question at this point whether the Arab air strikes are helping or hurting.  The Arabs have evidently been less than discriminating in trying to avoid civilian deaths, especially in the vital port city of Aden, where entire neighborhoods have been reduced to rubble.  The Houthis are grimly hanging on to most of the city, and pro-Hadi militias just aren't strong enough to dislodge them.  In its efforts to oust the Houthis, the Arab air force certainly isn't making any friends among the civilians who are trapped in Aden.

This makes the prospect of an eventual Saudi invasion more likely.  The "Arab Army" is 40,000 strong, but it's unknown what caveats have been negotiated by the Saudis for the participation of various countries.  Under what circumstances would Egypt allow its troops to join the ground coalition?  Or Jordan?  

With the immediate threat to the Kingdom receding, the Saudis may have a difficult time holding their coalition together.  So while they will continue to bomb and arm the army fighting the Houthis, any direct intervention by the Arab Army probably isn't in the cards.