If you look at it from one end, there was little to recommend Israel as a client state, in and of itself, relative to other states. Why not make Egypt a military collossus on behalf of the U.S.? Why indulge a nation of six million rather than its far more populous neighbors? U.S. public opinion is a factor, I would acknowledge, but is not sufficient to explain U.S. policy in support of Israel.
A factor in British thinking around and after WWI was Palestine's location in re: the Suez Canal and Britain's connection to India. But the Brits were not interested in limiting themselves to one client. The more the merrier. They were more interested in denying clients to Russia (and later, the USSR) and Germany.
Similarly, the interests of any would-be imperialism would logically be to enlist as many clients as possible in strategic locations.
A key caveat is that the actions of one client should not be so odious as to drive away other clients. So Israel can survive as long as it doesn't get too big for its britches. No Nile to Euphrates nonsense. It is all right for your clients to hate each other, not all right for them to destroy each other. Everybody is kept on a leash.
The Oslo process can be explained in this light as an ambitious effort to recast arrangements among clients who happen to be mutual enemies for the sake of regional stabilization.
Islamic and Jewish fundamentalism in the ME have both pushed this project off the rails. Fundamentalism has an autonomous, intransigent, volatile character that can get away from you -- the proverbial blowback.
This development feeds and is fed by the emergence of a new strategic orientation in the Son-of-Bush Administration, as discussed in Lemann's New Yorker piece. The adoption of agressive, military projection to pacify the U.S.'s Islamic clients and destroy the most recalcitrant ones (Iraq, Iran, Syria). Naturally in this scenario Israel's role is paramount. Not incidentally, Israel's most vociferous partisans are also those most committed to U.S. power projection.
In a nutshell, there are two alternative imperialisms in question here, each with their own cohort of apologists in the U.S. and associates in the ME, each moving to make the other untenable.
In this context, pipelines are a small part of the puzzle, just one stand of trees in the forest of the Great Game of this century -- control of Central Asia and the ME in conditions of increasing scarcity of oil.
mbs