Under a 1975 Memorandum of Understanding (MOU) the USA guaranteed all Israel's oil needs in the event of a crisis. This Memorandum of Understanding is quietly renewed every five years. It commits U.S. taxpayers to maintain a strategic U.S. reserve for Israel, equivalent to $3 billion in 2002 dollars. Special legislation was enacted to exempt Israel from restrictions on oil exports from the USA. Moreover, the U.S. government agreed to divert oil from the USA, even if this causes domestic shortages. The U.S. government also guaranteed delivery of oil in U.S. tankers if commercial shippers become unable or unwilling to carry oil from the USA to Israel.