Suez C Crisis - Why USA didn't join UK, France and Israel?

What were the reasons that USA opposed Suez C Crisis and put pressure on UK, FR and Israel to leave? USA was against the privatization of the C wasn't it? Why did US oppose its allies? With all three it had very strong relationships, so what were the reasons? [Political, Economic, Strategic reasons etc. PLEASE not common answers such as "because it was wrong, because USA supports freedom and democracy etc.]