Rachael Alexander: 'How fraught relations in the Gulf have brought us to the brink of war'
This week the prospect of an accidental war flaring up between the US and Iran came dangerously closer.
Iran's Revolutionary Guard fired a missile at a US drone on Thursday. Both gave different locations clashing on why and how it happened; but what exactly is behind the current tensions that have reached explosive levels?
Firstly, Iran said the drone was a legitimate target as it was flying over Iranian airspace in Hormozgan.
But US Central Command insisted it was an "unprovoked attack" in international airspace over the Strait of Hormuz.
The real truth is that the standoff between the US and Iran has been at boiling point over shipping in the Gulf of Oman.
Relationships have became more heated since Iran's threatened revival of its nuclear programme earlier this year.
Tehran is urging the European signatories to a 2015 nuclear deal to save the pact by next month - July 8 - or else it will start producing and stockpiling more low-enriched uranium than the deal allows.
However, the attacks on the oil tankers in the Strait of Hormuz inflamed things considerably.
While others remain unconvinced, Washington was quick to blame Iranian forces.
Any threat to the shipping industry which sees some 2,000 different companies with vessels in the zone would have massive international security implications.
Complicating matters further is the fact America has strong links with Saudi Arabia on whom it relies in the Middle East.
The Saudis blame Yemen's Houthi rebels for a rocket attack on a desalination plant this week.
Iran is a known backer of the Houthis in the civil war which has wracked Yemen.
Iran's nuclear role has long been a source of global contention. But Washington, under President Donald Trump, pulled out of the international agreement that had eased sanctions on Tehran in exchange for curbing its nuclear ambitions.
Crippling sanctions continue to bite in Iran.
However, things have escalated dramatically with the Iranian threat to once more start up uranium enrichment.
In response, the US sent a carrier strike group and missile battery to the Gulf.
When Tehran declared this week it would ignore the nuclear deal and breach its uranium limit if the other signatories do not salvage it, matters became more volatile.
Iran's threat was enough to prompt an announcement from the Pentagon that it would despatch 1,000 more troops to the Middle East.
Any possibility of confrontation instantly sends international alarm bells ringing.
Mr Trump has made many bellicose noises on being ready to use military force to block any Iranian ambitions in terms of getting their hands on nuclear weapons.
US dependence on oil supplies and their protection is also top priority. And there is nowhere more critical than the Strait of Hormuz as it links the Persian Gulf to the Gulf of Oman and the open ocean.
It is a vital corridor through which nearly 40pc of the world's crude oil passes.
Iran sits on its doorstep, a fact which Tehran has exploited in the past.
The country mined the strait before, and has threatened its closure.
Matters are further complicated by the political and religious dividing lines, which define the Middle East.
Saudi Arabia is hard-line Sunni Islam, constantly at odds with the Shia branch, as is the case in Iran.
They have used their proxies to stoke conflicts such as the civil war in Yemen.
This has pitted the Iran-backed Houthi rebels and a Saudi-aligned national government against each other.
The nightmare scenario would see oil tankers being targeted off the Iranian coast and declarations of war between Iran and Saudi Arabia. America has always provided the Saudis with military protection.
Iran has forged close ties with Moscow. This week Russian President Vladimir Putin warned any attack by Washington on Iran would have catastrophic consequences.
However, it is not the intended but the unintended consequences that could provoke a conflagration.