"The United States reiterates its steadfast commitment to Israel's security, including secure, defensible borders, and to preserve and strengthen Israel's capability to deter and defend itself, by itself, against any threat or possible combination of threats." This sentence appears halfway through a letter that US president George W. Bush presented to prime minister Ariel Sharon when the two met in Washington in April 2004 to discuss the planned disengagement from the Gaza Strip. While not said explicitly in the letter, Sharon said he understood the above sentence to mean that Israel had the right to preserve its policy of ambiguity regarding its undeclared nuclear arsenal and capability. Some foreign reports have estimated that Israel has 150 nuclear weapons. While the Bush letter of 2004 is not statutory, such letters are usually understood as binding on the next president - in this case Barack Obama. Israel's policy of ambiguity with regard to its undeclared nuclear capability is not likely to change in the near future. In April 2006, Dan Meridor, then a former justice minister and today a Likud minister in charge of intelligence agencies, presented a written version of Israel's defense doctrine to the government and the IDF. Together with a panel of a couple of dozen former military and intelligence officers, Meridor had been asked by Sharon to formulate Israel's defense doctrine for the first time since the establishment of the state. One of the first recommendations was not to change the policy of nuclear ambiguity. The Nuclear Non-Proliferation-Treaty (NPT), which Israel was asked to sign on Tuesday by the assistant secretary of state, has for a long time been interpreted in Israel as a failure. Established to stop the Germans from obtaining a nuclear weapon after World War II, the NPT was effective in South Africa's case - when the country abandoned its nuclear capability and signed the treaty - but has since, according to Israel, proven to be ineffective, particularly in two cases - Syria and Iran. Both Syria and Iran are signatories to the NPT. Syria was secretly building a nuclear reactor, in clear violation of the treaty, that was destroyed by an Israel Air Force bombing in September 2007. Iran is also believed to be developing a nuclear weapons program, in another violation of the treaty. "What the Americans are doing is rude," said Maj.-Gen. (res.) Ya'acov Amidror, who was a member of the Meridor panel that authored the defense doctrine. "After the failure of the NPT with Syria and Iran, it is ridiculous for a country with thousands of nuclear weapons to ask this from a country like Israel which is the only democracy in the Middle East and is under constant threat," Amidror said. Despite foreign reports and statements from the likes of former US president Jimmy Carter about Israel's nuclear capability, Israel's policy of ambiguity and longstanding decision "not to be the first to introduce nuclear weapons in the Middle East" is believed to still create an effective deterrent in the region. This will not change so Israel can sign a treaty that is anyhow perceived as ineffective.