Anything that stops Iran building a nuclear bomb, even temporarily, ought to be a good thing, right? The deal reached in Geneva, in which Iran agreed to scale back its uranium enrichment program in return for a partial lifting of sanctions, has been hailed as a breakthrough—particularly in US-Iran relations, which have been sour since the 1979-1981 US embassy hostage crisis. Yet it has invited harsh criticism from three quarters: US Republicans, Israel, and Iran’s Arab neighbors, especially Saudi Arabia.

(Background reading: If you’re not up to speed, we recommend CNN’s quick-and-easy primer on the nuclear dispute and the Guardian’s more detailed Q&A on what the deal entails.)

So is this just politics? Well, partly.

The deal requires Iran to stop producing uranium that could be used in a bomb. Weapons-grade uranium is at least 90% enriched—i.e., contains 90% or more of uranium-235, the unstable isotope that takes part in nuclear reactions. Uranium for civilian energy uses need only be 5% enriched. Iran has always denied it wants to make nuclear weapons, but has built up a stockpile of near-20%-enriched uranium. It has now agreed to stop enriching uranium above 5% and dilute the stockpile, as well as some other conditions. In return, sanctions will be eased, returning about $7 billion to Iran over the next six months.

So its nuclear program is merely restricted, not scrapped. But isn’t that better than no deal at all? Shouldn’t Israel, which lives in fear of a nuclear-armed Iran, welcome anything that puts bomb-building on hold?

Objection 1: Iran gets off too easily

Politics undoubtedly plays a part in Israel’s rejection. Israeli prime minister Binyamin Netanyahu is closely aligned with president Barack Obama’s Republican opponents, and both will seize any chance to criticize his policies.

But both have more genuine concerns too. A superficially similar deal with North Korea in 2005—halt the bomb program in return for aid—was soon flouted by the North Koreans. Moreover, Israeli intelligence reportedly believes that if Iran decides to renege on the deal, any bomb-making effort will have been delayed by only 24 days. On this view, the new Iranian president, the moderate-seeming Hassan Rouhani, is merely a fig-leaf for the more hardline clerical regime, and Iran is merely buying itself time.

Probably just as big an issue for Israeli and American hawks is the symbolism of the deal. The reward Iran is getting isn’t merely a few billion dollars of financial relief; it is, much more importantly, the beginning of the end of its pariah status. That shouldn’t happen, Israel argues, unless Iran abandons its nuclear efforts altogether. (Though one might retort that being a pariah didn’t stop Iran from having a nuclear program in the first place.)

Objection 2: Iran needs to be contained

Saudi Arabia, too, doesn’t want to see Iran rehabilitated, but for more complex reasons. Like the other predominantly Sunni Arab states, the Saudis see Shi’a Iran as a destabilizing influence in the Middle East, given its support for Islamist parties in Lebanon, Palestine, and elsewhere, and for Bashar al-Assad’s regime in Syria. Nukes or no nukes, they just don’t want Iran to regain its former clout. (Remember the Iran-Iraq war?)

And so, while the Saudi government has refrained from officially criticizing the nuclear deal—which would rile its close ally, the US—it’s allowed prominent Saudis to make the point instead. The head of the Shura Council, Saudi Arabia’s appointed quasi-parliament, said Arabs would “lose sleep” over the agreement, and Prince Alwaleed bin Talal, the Saudi business magnate, warns that Iran is playing on Obama’s political weakness and his desperation for a foreign-policy success.

The interview with Alwaleed, by Jeffrey Goldberg for Bloomberg, is worth reading in its entirety. It sets out the kingdom’s interests in the region, and its alliance with Israel and the US, with rare candor. Whatever you believe about Iran’s true intentions, it explains why the country’s neighbors are unlikely to give it the benefit of the doubt.