Must There Be US Foreign Aid to Israel?

I recently read of a troubling statistic:  the US has awarded more foreign aid to Israel than to any other nation.  Here is how the Congressional Research Service (CRS) Issue Brief words it:

Israel is not economically self-sufficient, and relies on foreign assistance and borrowing to maintain its economy. Since 1985, the United States has provided $3 billion in grants annually to Israel. Since 1976, Israel has been the largest annual recipient of U.S. foreign assistance, and is the largest cumulative recipient since World War II. In addition to U.S. assistance, it is estimated that Israel receives about $1 billion annually through philanthropy, an equal amount through short- and long- term commercial loans, and around $1 billion in Israel Bonds proceeds.

Israel is a nation of only 6.2 million, and $6 billion is equivalent to nearly 20% of the government's annual revenues ($38.5b in 2002; source CIA World Factbook).  It is a colossal sum.  Nearly all of the aid is provided without designation for use in particular development programs.  This too is exceptional.

Israel does receive aid on more favorable terms than other nations. For example, all economic aid is given directly to the Israeli government rather than allocated under a specific program.
-- from a report posted to the Jewish Virtual Library, A Division of the American-Israeli Cooperative Enterprise

I was trying to work out why I found this troubling.  I resent the provision of so much economic assistance to a nation with a per capita GDP that exceeds that of 190 other nations in the world, including nearly every nation in its region (even Kuwait and Saudi Arabia).  In the Middle East, only the United Arab Emirates and Qatar supersede Israel, and do so by less than $4000.  If you also consider that nearly 20% of Israel's population is Arab, the per capita GDP figure of non-Arab Israelis is even higher.

I read a comic book recently that asked "Must there be a Superman?" (DC Comics, 1972).  Bear with me.  Superman was being tried for crimes against humanity by the Guardians of the Universe, "a race of immortals whose self-appointed task is to survey and safeguard" the Milky Way and its inhabitants.  The Guardians allege that Superman's presence on Earth "directly contributes to the Terrans' cultural lag."  The idea works on Superman's mind:

For years I've been playing Big Brother to the Human Race!  Have I been wrong?  Are they depending on me too much...too often...? [...] I decide what's right or wrong--and then enforce my decision...by brute strength!

Upon his return to Earth, Superman counsels a group of migrant farm workers.  He says they don't need a superman, they need "a super-will to be guardians of your own destiny!"  He also arrests an earthquake and rescues a yacht.  The temptation to wield his awesome power to help those in need is too great for him to resist.

But what of Israel?  What is their need?  Is the US serving Israel, or does Israel serve the US?  Could the billions of dollars flowing into the tiny country actually be destabilizing?  If Israel is dependent on the US, why doesn't the US attach some strings to those payments, constrain the fashion in which the funds are spent, limit or eliminate aid in light of human rights transgressions, or disregard for World Court decisions?

Must there be US foreign aid to Israel?

It is difficult to imagine what the region would look like without US foreign aid to Israel.  Without Israel spending $9.11b (FY 2003) a year on the military.  Would the schism in the region be defused out of necessity?  Is the region irreversibly polarized?