These are perilous times in the Persian Gulf.

The region has largely been in free-fall since U.S. forces left Iraq in 2011.  Without the stability–and influence–that result from an American military presence, long-simmering ethnic and sectarian issues have moved back to the forefront, leading to increased Iranian influence in Iraq; abandonment of the Shia-led government by Sunni tribes in western provinces, and more recently, the rise of ISIS.

And if that’s not bad enough, there’s the twin catastrophe of the U.S.-Iranian nuclear deal.  Not only did the Obama Administration put Tehran on the glide slope for the nuclear club, they also agreed to release an estimated $150 billion in Iranian assets, long-frozen for the mullah’s support of terrorism and other misdeeds.  So, not only is Iran an inevitable nuclear power, they will soon be flush with cash to expand their ballistic missile program, support Hezbollah (and other terrorist groups), or fund covert nuclear efforts.

The Iranians are clearly feeling their oats, and not about to back down anytime soon.  Last October, Tehran test-fired a missile capable of carrying a nuclear warhead, in defiance of UN Security Council Resolution 1929.  Not that Iran was particularly worried; in response the White House said it might “consider additional steps,” which is diplo-speak for “don’t worry, we won’t do anything.”  Earlier today–almost three months after the test–the Obama Administration refused to explain why it is delaying new sanctions over the violation

Tehran’s latest act of military aggression came at year’s end.   As the USS Harry Truman transited the Strait of Hormuz, Iran suddenly announced plans for a live-fire exercise, launching rockets that landed within 1,500 yards of the American carrier.  The Pentagon did not reveal the incident until 30 December, after the Truman had returned to the Arabia Sea.  U.S. officials described the episode as “highly provocative.”  There was no threat of retaliatory action, despite the obvious threat to the carrier, other military vessels, and commercial ships in the area.

Fresh from that propaganda victory, Tehran set its sights on regional adversaries.  When Saudi Arabia executed Shia cleric Sheikh Nimr al-Nimr on Saturday, it touched off immediate protests in Iran. Demonstrators stormed the Saudi embassy in the Iranian capital and set it afire.  Representatives of the United Arab Emirates negotiated for the evacuation of Saudi diplomats and support staff from Iran, possibly preventing them from being taken prisoner.

In response, Riyadh has cut diplomatic ties with Tehran and suspended commercial flights between the two countries.  Neighboring Bahrain announced similar moves and the UAE said it was “downgrading” relations with Tehran.  Meanwhile, Iran’s Supreme Leader, Ayatollah Ali Khamenei, announced that Saudi Arabia would face “repercussions” for the cleric’s execution.

It’s worth noting that al-Nimr was not a particularly prominent cleric; indeed, key leaders of Saudi Arabia’s Shia minority took steps to distance themselves from the firebrand.  Al-Nimr advocated overthrow of the kingdom’s royal family, and outside assistance for the Shia population in Saudi Arabia’s eastern provinces, a call security officials equated with an invitation for an Iranian invasion.  But it gave Iran a new opportunity to put new pressure on its main regional rival.

If you’re looking for a common thread in all of this, it can be neatly summarized in the lack of American strategy and resolve in the Middle East.  President Obama’s desire to reach the nuclear accord with Iran has not only emboldened Khamenei and the rest of Iran’s theocracy, it has also raised doubts about our ability to support and protect allies in the region.  The lack of leadership from Washington is one reason that Saudi Arabia took the lead in military intervention against an Iranian-backed insurgency in Yemen.  While Mr. Obama is taking up his gun control crusade (again), the Persian Gulf is boiling over, and we clearly don’t have a clue, let alone a plan.

And the road ahead looks even more ominous.  Iran’s inevitable acquisition of nuclear weapons has left its neighbors looking at their own options–particularly as American power recedes further in the region.  Iranian nukes will be matched by Saudi Arabia and unlike Tehran, the kingdom won’t spend decades developing their own.  As we noted a few months back, Riyadh was a silent partner in Pakistan’s nuclear program, providing key financing with a promise that Islamabad would provide weapons to Saudi Arabia, in the event they were ever needed.

If that moment hasn’t arrived, it’s very, very close.  The Saudis already have intermediate missiles that can be easily modified to carry a nuclear warhead, and even with the current oil glut, they have the financial resources to acquire that technology quickly.  And it’s quite likely the UAE, Qatar, and other Gulf States will follow suit.

We’re on the verge of a nuclear arms race in the Persian Gulf–with more weapons in the hands of unstable governments (and limited restrictions on their employment) in the very near future.  If 2016 is shaping up as a scary year in that volatile region, it’s hard to fathom what 2020 or 2025 may look like.

In the interim, Saudi Arabia and the other gulf states perceive a clear U.S. tilt towards Iran, as noted by Eli Lake and Josh Rogin of Bloomberg. That perception will only accelerate the “go it alone trend” among our long-time allies, and generate more support for the “nuclear” option.