The impounding by Iran this week of another oil tanker making its way through the Strait of Hormuz is a reminder that the crisis in the Persian Gulf is far from over.
The Fars News Agency, which is associated with the Iranian Islamic Revolutionary Guards, claimed that the ship was Iraqi and carrying 700,000 litres of diesel fuel to an Arab country. Iraq has denied any knowledge of the craft.
This incident is the latest link in a chain of events that have brought the Gulf waterways (and Iraq) to a heightened state of tension not seen for several years. There are fears the standoff could deteriorate into an open armed clash between the US and Iran.
Events in the Gulf are part of a larger fraught reality in which Iran's main regional enemies, Israel and Saudi Arabia, are engaged in an undeclared conflict with Tehran. Tehran and Washington have mutually irreconcilable objectives regarding the Gulf, Iraq and the broader Middle East region. At the same time, neither side is seeking immediate confrontation.
Tehran and Washington have mutually irreconcilable objectives, but neither side wants immediate confrontation.
The current round of tensions is a product of the US decision in May last year to quit the Joint Comprehensive Plan of Action nuclear agreement. Secretary of State Mike Pompeo at that time outlined a new US strategy intended to contain and roll back Iranian gains in the Middle East.
Tehran has emerged as perhaps the most significant beneficiary of recent unrest in the Arabic-speaking world. As a result of instability during the past decade, and the application of Iranian methods of irregular warfare, Iranian proxy forces are prevalent in all of Lebanon and parts of Syria, Iraq and Yemen.
The harsh sanctions that followed the US decision to quit the JCPOA are intended to force the Iranians to cease or reduce their support to their proxies, draw back from their regional expansion and renegotiate an agreement that will put paid to their nuclear ambitions. Washington has sought to increase the pressure incrementally.
The Iranians are threatening to ensure that if they cannot export oil through the Gulf, neither will anyone else.
Since May, Tehran has looked to hit back. The Iranians appear to be seeking to ensure that if they cannot export oil through the Gulf, neither will anyone else.
Beginning on May 12, Iran appears (no direct responsibility has been claimed) to have carried out attacks on tankers attempting to traverse the Strait of Hormuz. About a third of the world's seaborne oil passes through this vital waterway. On June 13 an attack took place on Norwegian and Japanese tankers. A British-flagged tanker, the Stena Impero, was impounded on July 19. Iran also downed a US RQ-4 Global Hawk drone on June 20. The incidents have been accompanied by vague but threatening statements by pro-Iran Shia militia leaders directed at the US and its allies.
A Saudi Arabian oil pipeline and a provincial airport also have been targeted in recent weeks.
Israel is conducting a campaign against Iranian efforts to consolidate a land corridor across its areas of de facto control in Iraq, Syria and Lebanon, and thence to the Mediterranean and the border with the Jewish state.
The Iranians seek to supply their Hezbollah clients in Lebanon via this route. Israel is also concerned by indications Tehran wishes to deploy short-range ballistic missiles with its militias in the deserts of western Iraq. This would bring Israeli cities within range. Placing them with the militias also would have the benefit of deniability for the Iranians.
The militias are not an official part of the Iranian armed forces and, like Lebanese Hezbollah, can be presented as independent local actors. Against this background, reports that Israel carried out air raids on Badr Organisation targets in Iraq this month appear plausible. According to the reports, Israeli aircraft struck the Amerli and Camp Ashraf bases. If accurate, this means the scope of the Israeli-Iranian undeclared war in Syria has expanded to Iraq.
What may happen next? Bullish predictions from some US officials notwith-standing, Iran does not appear close to caving in as a result of the economic pressure.
The sanctions undoubtedly are having an impact on living standards for ordinary Iranians. But Iran showed in the pre-JCPOA years that sanctions alone will not cause it to change course. In 2012-14, when it was under harsh sanctions, Tehran nevertheless managed to assist the Assad regime in Syria to the tune of billions of dollars, to raise up the Shia militia mobilisation in Iraq and to finance its proxies in Yemen, Lebanon and elsewhere.
At the same time, Iran was aware that in a direct naval confrontation its forces would be rapidly destroyed by those of the vastly more powerful US. It is therefore likely to calibrate its responses carefully, in particular to avoid the loss of US life.
Tehran's responses to its enemies tend to be in direct inverse proportion to their strength.
For all its rhetoric, Tehran's responses to its enemies tend to be in direct inverse proportion to the enemies' strength. The least powerful adversaries - armed organisations such as the Iranian Kurdish PDKI and the Ahwazi Arab ASMLA - find their personnel targeted directly and murderously by Iranian state forces. Tankers flying the Norwegian, Emirati, British and Japanese flags have been targeted. Yet aside from a RQ-4 pilotless aircraft, the US has suffered no losses and there have been no direct attempts to kill American personnel or target US-flagged shipping. Iran may be seeking to keep its activities just below the level that would make a major US response unavoidable.
The Iranians are aware that next year is an election year in the US. They are cognisant, also, of the disinclination of Donald Trump's voting public and many of his generals towards further military commitments in the Middle East. They may have gathered the impression that the US President is reluctant to use force and that he sees the negotiating room as the place where he can assert himself and his country's interests.
Given all this, it is quite possible that the situation will not be brought to a head any time soon. Iran will continue to labour under sanctions but will refuse to substantially alter its regional stance or its position regarding its nuclear program. It will strive to keep up its levels of bothersome but manageable harassment in the Gulf and Iraq while hoping for a new occupant in the White House next year.
The US, Britain and other countries, in turn, will improve their readiness to prevent and deter the Iranian harassment in the Gulf and Iraq. The emergent US-led naval task force to protect merchant shipping transiting the Gulf is the latest evidence of this.
The situation is set to continue to simmer. A single spark could change everything. But, for now, there is no peace and no war in the Gulf.
Jonathan Spyer is director of the Middle East Center for Reporting and Analysis, and is a research fellow at the Middle East Forum and at the Jerusalem Institute for Security and Strategy.