Yeman was always a single country until Iran urged the Houthis, Shi'ites, to break away from the government, Sunni. The Houthis were successful in capturing much of Yemen before signing a peace agreement with the government. More recently, Iran urged the Houthis to break the agreement and try to capture all of Yemen with Iran's help. Saudi Arabia is helping the government to hold off the Houthi/Iranian attack. Look around the ME, Iran has done this same thing in Lebanon, now more of an Iranian province that a sovereign state, in Syria, now a failed state being exploited by Iran to further its own imperialist ambitions, and in Iraq, which Obama gifted to Iran when he withdrew our troops. Wars are raging across the ME and in every one of them Iran is supporting Shi'ites against Sunni. Without Iran, none of these wars would be happening.
I feel so sorry for the Saudis Let’s see them fight their own battles instead of hiring someone to do so
That's what a lot of Americans said about the Europeans, but FDR managed to get us into their war anyway.
Saudi Arabia attacked us on 9/11, Bush twiddled his thumbs until he came up with the brilliant pan to invade Iraq. It was plainly a diversion, like kicking a dog because someone stronger sucker punched you... But that was a an act of war. And Iran took over and kidnapped our Embassy workers for over 2 years and that was clearly an act of war, too...What the hell? Japan did that and we nuked them four years later...Are we so impotent and wimpy now?
Due to FDR's provocations and Germany's defense treaty with Japan. The Flying Tigers, American pilots being paid by the US, flying US planes and using US weapons had been shooting down Japanese planes in China for years; that is, the US was already fighting an undeclared war against Japan. FDR had been aching to enter that war for years and had promised Churchill he would find a way to.
Japan was at war in China over its own machinations, the I love 1940s America. We didn't equivocate over Pearl Harbor. No Senate hearings over which party/group/religion funded the attack . No fretting over how it might effect the world economy afterwards. Straight to the point. One mother loving day later, we were at war with the attackers. Americans have become of bunch of impotent wimps.
Since al Qaeda is a transnational organization, it is not possible to attack it as we were able to attack Japan, but we certainly have pursued them since 911. Iran has not yet done anything to us of the magnitude of Pearl Harbor, so it is not as clear what has to be done, but President Trump, I believe is on the right track.