This week's Times of London report quoting a Pentagon official that President George W. Bush has given Israel an "amber light" - somewhere between green and red - to prepare for possible military strike against Iran's nuclear facilities has generated a whirlwind of speculation in Israeli media circles. The timing of the Pentagon revelation also piques curiosity. It comes less than a week after the visit in Israel of Adm. Mike Mullen, chairman of the US Joint Chiefs of Staff, who reportedly warned Jerusalem that Washington has not given Israel a "green light" to do anything. These conflicting signals were further crossed by last week's visit of a former Pentagon official, Tony Cordesman. His central message also was that the United States had not "green lighted" a potential Israeli military strike against Iranian nuclear sites. It was Cordesman who asserted that this position had been communicated during Mullen's stopover. What is going on? Disinformation, or perhaps a heated debate in Washington into which Israel has been thrust in the middle? Cordesman's widely reported remarks at Hebrew University, Tel Aviv University and at the Jerusalem Center for Public Affairs may provide insight into the contradictory signaling from Washington. ASIDE FROM official visits by senior US administration officials, there is also a tendency in Israel to place great weight on the assessments of visiting former officials and senior analysts who have worked in top "brand name" government offices, such as the Pentagon and the State Department. However, not infrequently, Israeli officials, media and academia misunderstand the political and professional context - worldview, allies and adversaries - inside Washington's Beltway which shapes and influences the assessments of these visiting defense and intelligence insiders. Cordesman's own professional assessment, supported by robust quantitative analysis, was that the Iranian threat has been greatly overstated and that many of the regime's military capabilities, especially its conventional ones (but not its backing of regional terror proxies), are far weaker than has been previously suggested. Referring to a potential Israeli military strike, he said bluntly in a Channel 2 interview on July 8 that "Israel is entitled to make its own mistakes." At the same time, two other senior Bush administration officials, whose views on the Iranian threat and the US-Israeli strategic relationship differ sharply from Cordesman's, told this writer that the former Defense official "had not been authorized by the White House to speak on behalf of the president of the United States," adding that "at the end of a presidential administration, people say things and leak others that would not have occurred earlier in the administration." THE SUGGESTION here is that Cordesman's analysis reflects a particular underlying set of perceptions on the current state of the Iranian regime's ballistic missile capability and its nuclear weapons program, and US national interests in countering them, that are shared by some and discounted by others both in and outside the administration. In establishing context, it's important to note that Cordesman supported the November 2007 US National Intelligence Estimate which concluded that Iran had ceased its nuclear weapons program in 2003. He noted at the time, "It provides a major argument against any early military action against Iran, and it refutes much of the hard-line rhetoric emerging from various neoconservatives. In broad terms it reinforces the pro-negotiation positions of Secretary [of State Condoleezza] Rice, Secretary [of Defense Robert] Gates, Admiral Mullen, and [former Central Command chief) Admiral [William] Fallon." In contrast, former undersecretary of state for nuclear proliferation and then ambassador to the UN John Bolton labeled the NIE as "politics masquerading as intelligence." The NIE top line conclusion was also dismissed by other administration officials. In addition, heavy criticism was voiced in key European and Israeli intelligence and military circles. The disagreement revealed a deep fissure within the administration and senior Washington circles over which approach to take on Iran's nuclear file. IN THE case of Iran, the split between the "neoconservative" view and the assessment of Cordesman and others includes another dimension. Neocons proffer the view - which Cordesman outrightly rejects, as he clarified this past week - that the Iranian nuclear threat is increased by President Mahmoud Ahmadinejad's commitment to Shi'ite messianism and its mandate to trigger the return of the hidden imam, the Shi'ite messianic figure, from his current state of occultation, a commitment shared by other hard-line Iranian regime leaders and clerics. Cordesman and his school of thought have suggested that Ahmadinejad's religiously based declarations to destroy Israel, achieve nuclear capability and assume leadership of the Middle East in the name of the mahdi merely reflect his honed skills at brinksmanship and shrewd Iranian domestic politics. Cordesman suggested that Ahmadinejad is no less rational an actor than Bush or other Western leaders. Cordesman's dismissal of the religious and ideological underpinning of the regime stands in sharp opposition to Bush's views, as well as those of Islamic affairs experts in the Pentagon, vice president's office, and the preeminent scholar of Islam, Prof. Bernard Lewis. Cordesman's own assessments this week of Iranian force structures, weapons inventories and future attack scenarios did not - and in his view should not - factor in that which is unquantifiable, meaning the religious motivation and readiness of the regime to mobilize radical Shi'ite and Sunni Islamic terror proxies across the region, to use nuclear weapons, and to strive for regional and ultimately global supremacy. Israeli officials and shapers of public opinion in Israel should listen attentively to outside assessments from Washington. However, Israelis must also integrate the kinds of sharp intellectual, political and strategic differences in world views as noted above among US officials and former US officials, even when they share political affiliations. The writer is director of the Institute for Contemporary Affairs in Jerusalem.