Thousands of Cases of Dengue Fever Reported in Yemen: UN

The Houthis are supported and given weapons by Iran which is primarily Shia Muslim along with the Houthis.

ISIS is supported by rich extremist Sunnis around the world financially and also by their sons and daughters sometimes too as soldiers and wives of ISIS Soldiers.

But, the Saudis Bombing the Houthis can only destroy their weapons like tanks, planes, artillery and bomb depots and munitions depots throughout Yemen. It really cannot ultimately defeat the average Houthi with an Ak-47 and a Shoulder fired grenade launcher.

The problem is exactly the same in regard to ISIS. The U.S. and Europe can bomb ISIS ongoing for years likely and it will get rid of all Tanks, planes, artillery and bomb depots and munitions depots that aren't buried deep in the sand somewhere that no one knows (both the Houthis and ISIS) similar to Saddam Hussein burying fighter jets so the U.S wouldn't destroy them deep in the sand in unknown places.

But, like I said this does not destroy the guerrilla warriors of the Houthis by the Saudis nor ISIS by the U.S. and Europe and all Saudi and Shia governments in the Middle East and beyond.