As the US and Iran prepare for a dialogue that could have far-reaching consequences for the Middle East, there are signs of growing strain between the US and its key regional ally, Israel. It is unlikely at this stage that the 50-year-old alliance is in serious jeopardy, but clear that if neither America's new and idealistic president, Barack Obama, nor Israel's combatative prime minister and right-wing hawk, Benjamin Netanyahu, step back from their current positions, a collision is inevitable.
The coming weeks, following their May meetings, will be crucial for the entire Middle East and US-Israeli relations in particular.
Israel's vehement opposition to talks with Iran's leadership, which many Israelis view in Netanyahu's own words as "a messianic apocalyptic cult" that will soon possess nuclear weapons, may simply be a bluff before the Americans sit down to talk with their leading adversary in the region.
But the strains seem to be genuine and the consequences of this confrontation could be startling.
Israel's new government seems tailor-made for conflict with an administration in Washington that supports a Palestinian state and is expected to push for progress on drawing borders.
Not since 1991, when US President George H. Bush, went toe-to-toe with Prime Minister Yitzhak Shamir over Israel's accelerated settlement expansion in the West Bank and its rejection of a proposed peace conference in the aftermath of the 1990-91 Gulf War against Saddam Hussein, have US-Israeli relations been so tense.
Political analyst Gerald Steinberg of Israel's Bar-Ilan University warned that if Obama puts too much pressure on Netanyahu over such explosive issues as West Bank settlements "it is likely to lead to a major confrontation". Qwais Abuleila, a member of the Palestinian parliament, believes Washington "cannot avoid the challenge forever ... If the United States wants to keep its credibility, they have to have the courage to confront them," he declared.
The new US administration's approach to Iran has "stirred doubts in Israel's heterogeneous government about Obama's commitment to Israel's security, as Netanyahu defines it," Jim Hoagland, the veteran international affairs writer observed. "These misgivings create a queasiness between the two allies that cannot be publicly discussed."
Obama's high-profile approach to Iran to engage in diplomatic dialogue to iron out their many differences has sent shivers of alarm through Israel's right-wing government and its military establishment, which views Iran's alleged nuclear weapons programme as an existential threat that must be eliminated within the next few months.
US negotiations with Tehran, these officials argue, will only give Iran more time to develop nuclear weapons whose first target will be Israel. These officials appear to favour a pre-emptive and unilateral Israeli air and missile strike against Iran, whatever the Americans may think.
US media reports in April that Obama might cede Iran's rights to a nuclear programme have inflamed Washington's relations with Netanyahu's government even further.
The White House's renewed focus on the Arab-Israeli peace process (or what's left of it) is also being challenged by the hawkish "Bibi" Netanyahu (no advocate of compromise) and even more so by his ultra-nationalist foreign minister...