To the question about why: because in the Middle East it’s all about spreading your version of Islam.
Saudi Arabia is the main cause of destabilization in the Middle East since the 1980s and their initiative to spread Wahhabism. But the truth is the dispute between the Saudis and Yemen goes back to the 1930s, when Saudi Arabia was formed they took land from Yemen for their kingdom.
The Houthi are a Shia sect, which makes them a natural ally of Iran because in the ME it’s all about what branch of Islam you claim. But the Houthi are a sort of weird version of Shia but that’s a whole another discussion.
The saudis sent settlers into Yemen to spread their Sunni Islam, which lead to a number of wars in the early 2000s between the Saudis and the Houthi in Yemen. The bad blood is deep.
The Houthi got their Shiite together and took the Yemen Capitol in 2015 and it’s been total war since. Hundreds of thousands of Yemenis dead, bombed schools and hospitals, hundreds of thousands of children that starved to death, etc. It’s the worst on the planet for four years running.
No one is really sure about the relationship between Iran and the Houthi. They are not in operational alignment but Iran does give weapons and money support, most likely the drones used were Iranian.
And here we are.
Were the drones launched from Iran, I highly - Highly - doubt that.
Were they smuggled into Saudi Arabia and launched closer than we think, that’s my suspicion.
Either way the USA does not belong in this conflict at all. We have no part and any attempt to get us involved is folly.