Iraq, its neighbors, and Israel
If the United States invades Iraq and leaves troops there for a number of years, as they have done, for example, in Korea (35 thousand troops), then by looking at this map you will note that the so-called Axis of Evil is totally boxed in. Turkey to the North, our ally, Iran to the one side; Syria and its client state Lebanon, on the other side; Jordan and Saudi Arabia. similarly close to Iraqi borders. This to me suggests that Israel will have a strong friend (the U.S.) in the middle of a hot spot, a friend able to launch an offensive with ease from Iraq if the need should arise, and perhaps being so stationed, cause a cooling down of the Arab hostility toward Israel.
For map (it is interactive) see: Iraq and its neighbors