Why are we not cutting defense spending?

The president is saying that he is proposing making cuts in social programs but no details on defense. Why wouldn't he cut the defense budget? Right now it's at around $680 BILLION. The country with the next highest military budget is china that spends 100 Billion. We have a higher military budget than the next 25 countries combined 24 of which we are allied with 8 of which are a members of NORAD. We make up 40% of the worlds military expenditure. And yes I realize we are in the middle of a war but I don't think we need a $150 million f-22 fighter jet when we are facing an enemy without an air force. I don't think we need to spend 9.9 billion on ballistic missile defense program when our enemies have no ballistic missiles and good luck shooting a missile with a missile that's like shooting a bullet with a bullet. I don't think we need to spend 5.4 billion dollars on submarines when we are against a land locked country. This is just logic. If we want to cut the deficit we should at least make an effort to cut the defense budget as well as social security and medicare.