"It is the assessment of the U.S. government that Iran is responsible for today's attacks in the Gulf of Oman" Credit: @SecPompeo

For the next 60 days, the 90-mile length of waterway known as the Strait of Hormuz will be the most dangerous place on Earth, with the prospects for an incident occurring which will trigger a regional conflict possessing global ramifications high. Following this 60-day period, the risks will only grow higher.

On July 1, Iran announced that it was exceeding some of the uranium enrichment restrictions put in place by the Joint Comprehensive Program of Action, or JCPOA (better known as the Iran nuclear agreement), which the U.S. withdrew from a year ago.

The decision to blow through the restriction were a response to Washington’s “maximum pressure” campaign to to negotiate a new deal. This campaign has included the resumption of crippling economic sanctions, including the implementation of so-called “secondary sanctions” which target nations and companies that do business with Iran in violation of the embargoes.

Iran and the other parties to the JCPOA have sought to keep the agreement alive by finding workarounds so Iran can continue to sell oil, the lifeblood of its economy. These efforts have failed, putting Iran in the difficult position of committing economic suicide by continuing to comply with the nuclear agreement.

So backed into the corner, Iran has nowexceeded the limits placed on the amount of low-enriched uranium it can stockpile, as well as the level to which it is enriching uranium. While the International Atomic Energy Agency (IAEA) has confirmed that Iran has increased its enrichment level to 4.5 percent, Iran is far removed from the 80 percent or more needed for a nuclear weapon.

Tehran, meanwhile, has given the EU 60 days to come up with a solution to the issue of restoration of trade. Otherwise, at the end of that period, Iran will continue to peel away JCPOA restrictions until none remain. The U.S. and Israel have condemned Iran’s actions, and have threatened military action if Iran were to embark on a path that led to the creation of a nuclear weapons.

But the more immediate danger, today, it is the continued economic squeeze applied by the U.S. that threatens to ignite the tinderbox that is the Persian Gulf.

The most recent manifestation of this campaign came on July 6 when the British government, under pressure from the U.S., intercepted, boarded, and seized an oil tanker, the Panamanian-flagged Grace 1, off the coast of Gibraltar. The Grace 1 was carrying some 2.1 million barrels of crude oil believed to have originated in Iran and being transported to Syria in violation of EU sanctions. The British action was immediately condemned as illegal by Iran, which vowed to retaliate in kind by seizing a British oil tanker in the Persian Gulf. This Iranian threat led to the British increasing the security level for ships transiting the Strait of Hormuz, and deploying a British Frigate, the HMS Montrose, to serve as an escort for British shipping transiting the Strait.

Furthermore, an incident occurred on July 11 where the British accused the Iranian Revolutionary Guard Command navy of trying to seize a British-flagged tanker, the British Heritage, as it transited the Strait of Hormuz. According to the British, only the intervention of the HMS Montrose, which trained its guns on the Iranian vessels in question, prevented the Iranians from seizing the tanker. Iran quickly denied that such an incident occurred but noted that British shipping would be at risk should a speedy resolution to the Grace 1 incident not be forthcoming.

The actual events surrounding the incident between Iran and the British Heritage are far more nuanced that the media accounts report. The British Heritage was on its way to Basra to pick up a load of oil when, following the seizure of the Grace 1 on July 6, it was ordered to turn around and return home. The tanker remained anchored off the coast of Saudi Arabia, fearful of being seized by the Iranians if it were to transit the Strait of Hormuz unescorted. The incident in question did not take place in the established shipping lanes normally used when transiting the Strait of Hormuz, but rather in the contested waters off the Iranian-controlled Island of Abu Musa, which is also claimed by the UAE.

The decision on the part of the British to transit using the waters south of Abu Musa was made in full recognition of the risks posed by such a journey. In May of 2015 theIRGC attempted to halt a Singapore-flagged merchant ship, the MT Alpine Eternity, as it passed through disputed waters south of Abu Musa island; the Iranian ships dispersed once the Alpine Eternity entered UAE territorial waters and UAE Coast Guard vessels responded.

The incident with the Alpine Eternity came one month after theIranian Navy diverted and seized a Marshall Islands-flagged vessel, the Maersk Tigris, while it transited the Strait of Hormuz using an established sea lane nominally protected under the Rights of Straits Passage, part of aUN convention granting free passage through strategic shipping choke points such as the Strait of Hormuz, the Strait of Gibraltar and the Malacca Strait. However, Iran claimed that it had an outstanding legal claim against the Danish company, Maersk, that owned the Maersk Tigris, and that it seized the ship as part of an effort to get restitution for this claim.

By seizing the Maersk Tigris while transiting inside a well-established sea lane ostensibly protected under international law, Iran put the international shipping community on notice that it would enforce Iranian law in Iranian territorial waters, and that the Rights of Straits Passage did not provide immunity from such enforcement. The MT Alpine Eternity was cognizant of this new reality when it sought to avoid the established shipping lane exiting the Persian Gulf that runs between Abu Musa Island and the Tunb Islands, and which is well within Iranian territorial waters.

It appears that the British Heritage was attempting a similar avoidance strategy when it came too close to Abu Musa. Far from attempting to seize the British ship, the Iranian patrol boats were simply doing what all navies do when foreign vessels violate their protected territorial waters—they investigated. There is little doubt that had it not been for the intervention of HMS Montrose the Iranians would have made an effort to divert the British Heritage to Abu Musa, where it would have been boarded and the ship’s crew questioned and likely arrested. But I believe that this incident was not part of a premeditated Iranian effort at retaliation over the seizure of the Grace 1 off Gibraltar, but rather a reasonable reaction to a violation of its territorial waters brought on by British actions which, given the history and known nautical limitations of the southern Abu Musa transit, the British had to know before hand could lead to a confrontation.

But this does not mean that Iran will not provoke such an incident—far from it. The British seizure of the Grace 1 represented an escalation of hostilities between the UK and Iran for which Iran has promised a response. If history is a judge of such statements, British shipping in the Strait of Hormuz will be at risk—but not now. Iran is, if anything, a prisoner of legal procedure, and so long as the Grace 1 case is transiting the EU court system, British shipping should be able to transit protected sea lanes without incident.

Evidence in support of this theory comes in the form of thejourney of the Pacific Voyager, a British-flagged oil tanker which departed the Persian Gulf along the same route that the British Heritage would take, skirting south of Abu Musa island. Like the British Heritage, the Pacific Voyager was escorted by HMS Montrose. Given the fact that the Pacific Voyager, unlike the British Heritage, was carrying a full load of crude oil, it would have made a perfect candidate for any tit-for-tat retaliation over the seizure of the Grace 1. The Iranians ignored the Pacific Voyager, an indication that, unlike the British Heritage, it did not violate Iranian-claimed territorial waters off Abu Musa island.

The Grace 1 incident will continue to resonate in the days and weeks to come. The British are now saying that it will return the tanker if the Iranians promise the oil will not be delivered to Syria. Meanwhile, Iran has made it clear it will retaliate by seizing a British ship if the Grace 1 is not released in a timely fashion. If Iran tries to seize a British ship in the Strait of Hormuz, or is wrongly perceived as attempting to do so, the likelihood of a military clash between the British (and possibly U.S.) navy and Iran is significant. This is the most likely trigger for war in the region over the course of the next 60 days.

This puts not only the 36 U.S. military bases in the region at risk, but also all of Israel, as well as the oil production infrastructure of the Gulf Arab states. Moreover, Iran could completely shut down the Strait of Hormuz, cutting off 30 percent of the global oil supply, devastating the global economy.

All of this makes the Strait of Hormuz the most dangerous place in the world today.

Until the 60-day deadline set by Iran on its nuclear demands expires. Then it will become even more so.

Scott Ritter is a former Marine Corps intelligence officer who served in the former Soviet Union implementing arms control treaties, in the Persian Gulf during Operation Desert Storm, and in Iraq overseeing the disarmament of WMD.