It's always possible that someone besides Mossad carried out the assassination of Mahmoud al-Mabhouh, a top Hamas military commander, in a Dubai hotel in January. Israel has refused to comment; on Monday Foreign Minister Avigdor Lieberman explained the silence by saying there is "no proof" Israel was responsible. But the Dubai police insist they are "99%" certain that Israel's famed intelligence agency did the deed. The Dubai authorities say they caught the 11-member hit team on videotape moments before and after they allegedly smothered Mabhouh with a pillow in his hotel room — some reports have it as an injection of a chemical that induces a heart attack — and also at the airport as they left the country immediately afterward. But since Israel is well known to have carried out such daring targeted killings in the past, most observers in the region — including in Israel — have come to the same conclusion.But unlike such assassinations in the past, this one could have serious diplomatic consequences for Israel. It would appear that whoever was responsible underestimated Dubai's security capability. The city-state used sophisticated computer programs to quickly sift through its massive pool of security-camera footage and pinpoint the movements and travel documents of the alleged killers. More embarrassingly, the Dubai authorities are claiming that the hit team stole the identities of Israeli dual-national citizens, and traveled into Dubai using false British, Irish and French passports. Now the governments of those countries are promising swift investigations into the matter, while the European media — especially in Britain — are asking whether or not those governments were forewarned of the operation. Meanwhile, Dubai is demanding that Interpol issue an arrest warrant for the chief of Mossad. While such an action is unlikely, the moderate Arab city-state's commitment to pursue the case will be hard for its Western allies to ignore.Israel's intelligence establishment — and some of its press — are predicting that the shock and outrage surrounding the case are overdone and will blow over. All countries fighting foreign terrorists, they say, have to engage in the occasional bit of wet work, and the Hamas commander — apparently the man in charge of taking weapons into Gaza — was a legitimate target in such spy games. "Past experience shows that disputes in this area tend to be treated as belonging to the special, sealed-off category of 'national security,'" wrote Jonathan Spyer in the Jerusalem Post. "Where states have good reasons to maintain healthy ties with one another, such incidents are rarely allowed to muddy the waters for long."But such a view miscalculates the degree to which Israel's relations with its Western allies are changing. Israel's unilateral security and military actions — as justifiable and as effective as they may be — are souring world opinion against the Jewish State. Israel's role in the Western press is less and less that of embattled David and more and more the reckless Goliath: from the ongoing siege of Gaza to the intentionally disproportionate responses during both the war in Lebanon against Hizballah in 2006 and the war in Gaza against Hamas in 2009. Such views are stronger in Europe than in the U.S., which is why the scandal surrounding Mossad's alleged use of European passports could gain momentum there.But relations between the U.S. and Israel are also in a fragile phase. During the Cold War, Israel could claim to be safeguarding American interests against the Soviet-backed armies of Syria, Iraq and Egypt, in a global struggle for a free world. The attitude was summed up by a T-shirt that appeared in Israel in the 1980s of an American fighter plane (presumably one sold to Israel) with the slogan, "Don't Worry America, Israel Is Behind You."But the Cold War is over, and Israel and its allies in the West now tout the Jewish state as an ally in the so-called war on terror. But in fact, the militant Palestinian and Lebanese groups engaged in a territorial war with Israel are the sworn enemies of the al-Qaeda-inspired radical extremists who are at war with the West. In the struggle against Islamic extremism, Israel risks becoming less of an asset to America and more of a liability. The Obama White House, recognizing that the ongoing Arab-Israeli conflict is a recruiting tool for radical Islam, has said that peace in the Middle East is a matter of U.S. national security.Rather than the war of terror, the current paradigm for the strategic relationship between America and Israel is the cold war against Iran and its allies — Hamas, Hizballah and Syria — for Middle East supremacy that began after the invasion of Iraq. On a military level, ties between America and Israel have never been stronger — the two countries staged their largest ever joint military exercise last year. But most Americans don't really want to be part of a war for Middle Eastern supremacy — they want the U.S. out of Iraq and Afghanistan as quickly as possible and for their government to spend that money creating jobs at home.Which is why unilateral Israeli military and intelligence operations could potentially be damaging to Israeli-American relations. With the peace process moribund, with Hizballah re-armed and stronger than ever and nuclear talks with Iran at a dead end, the Middle East is on the brink of a regional war that could be sparked by any number of incidents. From its air raid on a suspected nuclear facility in Syria in 2007 and the assassination of Hizballah operations chief Imad Mughniyah (which was also attributed to Mossad) in 2008 to the Dubai job, Israel — by action or by reputation — is notching up a series of scores that its Arab enemies are promising to settle.The Mabhouh case now has Hamas officials vowing revenge — after months of an uneasy truce between Hamas and Israel. Talks between Israel and Hamas over a prisoner swap to free captured Israeli Gilad Shalit are effectively dead, a Hamas official in Beirut told TIME. If a unilateral Israeli operation like this — or an air strike against Iran's nuclear facilities — ends up increasing the risks for American soldiers in Iraq or Afghanistan, the U.S. public's romance with Israel may finally begin to sour.— With reporting by Rami Aysha / Beirut