Your still wet behind the ears when it comes to national policy. The IG was investigating whether the arms deal was an emergency and the behaviors of Iran last year targeting shipping vessels deemed it was. Add on the factor that if Saudi Arabia had wanted to they could have just gone to China and Russia for arms making them a more dominate global player not just for arms but influence over the region. The real reason the house and senate over rode the sale was because of the killing of Khashoggi, maybe not so much for the house but the senate over ride was mostly symbolic. Before the sale went through they obviously knew in advance Trump would veto it and they wouldn't have had enough votes to over ride it....but personally I think that was already set in motion between some in the senate as that's is just how vital a national security interest it is other wise they wouldn't have over rode the sale. Besides that we are talking billions of dollars in arm sales...why should the US not make that money just because some guy was stupid enough to want to get married so bad he put his life at risk to do it. We are suppose to lose influence and billions of dollars just because one guy made a fatal decision. Trump also started losing confidence in the guy after leaks to the media last year. It's one thing to be investigating but it's another to leak what they are investigating. If you ask me this was getting petty when he decides to investigate dog walking by an aide. It's just general nick picking at everything this administration is doing like always and it has to stop, the only way to get it to stop is to take out those with their own political agenda instead of following the procedures and processes being set forth by this administration.