In 1969, the Nixon administration was concerned about Israel's alleged possession of nuclear weapons and the possibility of an arms race in the Middle East, The New York Times reported Thursday. "The Israelis, who are one of the few peoples whose survival is genuinely threatened, are probably more likely than almost any other country to actually use their nuclear weapons," Henry Kissinger, former US president Richard Nixon's national security adviser, warned in a memorandum dated July 19, 1969, part of a newly released trove of documents. The Nixon administration's concerns were detailed in documents from the Nixon Presidential Library, the Times said. By law all classified documents must be reviewed and possibly declassified after 25 years. The documents provide insights into America's relationship with Israel and reveal tensions in the relationship regarding Israel's nuclear weapons, a source of disagreement in the US-Israel alliance. Kissinger wrote about the difficulty of convincing Israel to abandon its nuclear program, and his concern that Israel may have stolen nuclear-related material from the US. "This is one program on which the Israelis have persistently deceived us," Kissinger said, "and may even have stolen from us." Kissinger presented the option of pretending that the US was not aware of Israel's nuclear weapons and maintaining deliberate ambiguity. Another option he laid forward was to withhold Phantom fighter jets from Israel as an incentive to cooperate on the nuclear issue, according to the Times. "Israel will not take us seriously on the nuclear issue unless they believe we are prepared to withhold something they very much need," he wrote. "On the other hand, if we withhold the Phantoms and they make this fact public in the United States, enormous political pressure will be mounted on us," Kissinger went on. "We will be in an indefensible position if we cannot state why we are withholding the planes. Yet if we explain our position publicly, we will be the ones to make Israel's possession of nuclear weapons public with all the international consequences this entails." Some of the consequences that Kissinger feared might have been to "spark a Soviet nuclear guarantee for the Arabs, tighten the Soviet hold on the Arabs and increase the danger of our involvement," Kissinger wrote at another point. The documents also contain snippets about Washington's attempt to manipulate relations with Saudi Arabia to broker a Middle East peace deal, and discussion of supporting a Kurdish uprising in Iraq, the Times reported.