Well if the US didn't support Israel it likely wouldn't be there anymore... and either the situation would be exactly the same but opposite. (The Israelies are now then palastinians.) They would all be kicked out (with many casulaties along the way). Or they'd all be dead.
Also we'd have one less friendly nation in the region. So we'd have... no friendly nations in the region except for a couple that act polite because they like our buisness.
It reminds me of my biggest fault with the government and the UN. The lack of action against genocides. After world war 2 I thought the motto was "Never Again." However instead it's "Just about all the time."
The best the UN ever does is send troops over to observe the massacres with orders to not do anything about it. Cause that's always great. Lets let people be ethnically cleansed AND horribly traumatize people for life.
Now those are places i'd actually like to see "Nation Building" attempted. However it never benefits anyone to ever help these places so they don't get help.
