If you want to understand just how special the U.S.-Israel relationship really is, look no further than the annual aid package. Israel is not only the greatest beneficiary of U.S. defense assistance, but also the only one allowed to spend a portion of that assistance on weapons and equipment from its own industry. Everyone else has to buy American.

President Barack Obama is now looking to end this U.S. subsidy of Israel's defense sector, according to U.S. and Israeli officials. They say the "offshore procurement" provision, unique to Israel's aid package, is one of the last obstacles to completing an agreement to extend aid until 2029. Obama would like to phase out the agreement that allows Israel to spend 26 percent of U.S. annual aid at home. Prime Minister Benjamin Netanyahu, so far, disagrees.

In one respect this is surprising. Obama and his supporters like to tout U.S. military aid to Israel as an act of the president's unprecedented generosity. The U.S. has given Israel nearly $24 billion under Obama, more than any other U.S. president. As National Security Adviser Susan Rice said this month, "Even in these days of belt tightening, we are prepared to sign the single largest military assistance package — with any country — in American history," adding that it today comprises more than 50 percent of the total U.S. military aid budget.