Reuters reports a Saudi official responding to the Iranian nuclear deal by saying it could “mean a ‘happy day’ if it stops the country gaining a nuclear arsenal,” but it would be bad news if the deal enables Iran to “wreak havoc in the region.”

The official also said Iran had “destabilized the whole Middle East through its activities in Iraq, Syria, Lebanon and Yemen.” It was able to do all this damage without a nuclear umbrella, so the Saudis warned that “if the deal allowed it concessions, the region would become more dangerous.”

A Saudi diplomat quoted by The Washington Post called the nuclear deal “extremely dangerous” and “said it would give a green light to his own government to start a nuclear energy program.”

“The feeling among the Gulf leaders is that the Americans wanted to make a deal before the end of Obama’s term, at the expense of regional security,” the anonymous Saudi diplomat continued. “If sanctions are lifted, Iran will try even harder to redesign the region. Iran may see this as acceptance from America to play a bigger role.”

The same article mentions that Arab states are as worried about the danger of growing Iranian prestige and financial strength as they are about its nuclear program.

President Obama’s best-case scenario is that Iran is eight to ten years away from a nuke – down from earlier claims of 10 to 13 years – and even that estimate is considered wishful thinking by serious analysts. One of the key concessions extracted by Iran is that America and the U.N. will formally admit it has a right to a nuclear program. They make the occasional pro forma promises that they only want nuclear power for peaceful civilian uses, but nobody believes them, least of all the Iranians currently dancing in the streets.

Saudi Arabia most certainly does not think Iran will stop with building peaceful nuclear power plants. There is much talk about “tensions” being “relieved” by the nuclear deal, but in truth, the more likely outcome is a regional arms race, and the Saudis will participate. Iranian adversaries who consider swearing off their own nuclear deterrents in exchange for U.S. protection can ask the Ukrainians how well such an arrangement worked out for them.

Israel’s ambassador to the U.S., Ron Dermer, put it well in an address to Christians United for Israel, noting that the nations most immediately affected by an emboldened, enriched, soon-to-be-nuclear Iran weren’t represented at the long, dreary nuclear talks with Iran:

Israel is not there. Your Arab allies are not there. Those who are the most vulnerable, those who would be the most endangered by any deal – we are not at the negotiating table. And as the old saying goes, if you’re not seated at the table, then you’re probably on the menu.

“When Israel and the Arab states are on the same page – which happens about once a century – pay attention,” Dermer added. If Middle Eastern powers interpret Obama’s cave to Iran as the sunset of American influence in the region, with the dawn of an aggressive Iranian hegemon backed by Russia, they will be looking for mutual support as well as nuclear deterrence. (The Saudi diplomat quoted by The Washington Post also mentioned the possibility of looking to “other partners like China if America is giving everything to Iran.”)

On the other hand, there is always the possibility that pragmatic states will make their peace with the new regional super-power. The Washington Post mentions the United Arab Emirates sidling up to Tehran, along with Qatar and Oman, and maybe even Turkey, which is hungry for Iranian oil. The Saudis may conclude it is more important to bargain for a good position in the Iran-dominated Middle East than to strenuously oppose the new order.

One other wild card to consider is ISIS. As Obama draws American power down and hands leadership off to Iran, it is increasingly likely the Iranians will receive the credit for any significant defeat of the Islamic State, which would be a huge boost to their regional prestige – all but guaranteeing a pan-Shiite lock that either partitions Iraq or makes Iraq into a de facto Iranian client state. However, a big part of ISIS’ appeal to its recruits and captured populations is that it represents the best hope of preserving Sunni Islam and opposing Shiite domination. They are making that sales pitch in Saudi Arabia right now, along with bombing Shiite mosques to stir up sectarian tensions.