It is no surprise that Israel and the GCC states are nervous about the rapprochement between the US and Iran. They do not have to look hard to find reasons to worry.
Tehran has only agreed an interim, six-month arrangement so far, but if it manages to seal a permanent deal within a year, which is the target that negotiators have set themselves, it could create some significant waves.
For a start there will be a new rival for Washingtons affections in the region, potentially diluting the impact of what Saudis, Israelis and others have to say to those in the White House.
There will be economic consequences too. If Iranian oil starts to flow back on to the international market it is likely to force down the price of crude at a time when the Gulf states have become ever more reliant on high oil revenues to balance their budgets.
More worrying, perhaps, is the idea of an emboldened Tehran stepping up its support for militant groups in Lebanon, Iraq and Gaza and for the Al-Assad regime in Syria.
But the longer-term benefits from a deal to end the international standoff with Iran are worth such risks. The US and the other powers involved in the talks will of course listen to the concerns of their regional allies, but they should push ahead anyway.
Fundamentally, a Gulf without the prospect of a nuclear-armed Iran means a safer life for everyone. That cannot be achieved by military means. It has to happen through diplomacy.
In the longer term, if Iran sees advantages from dealing with the world around a negotiating table rather than via bombast and its terrorist allies bomb blasts, then that too holds myriad possible benefits. It may seem fanciful to think Tehran would waver in its support for Al-Assad, Hezbollah or Hamas, but then again no one anticipated how quickly a breakthrough would be made in the talks over its nuclear programme.
The next six months will offer plenty of opportunities for all sides to test their assumptions about each other. There will no doubt be allegations of backsliding and commitments being reneged on. It will be a test of patience, diplomatic resolve and courage, but the prize is worth fighting for.