Ever since the bureaucrats of Britain and France made a pig’s ear of their arbitrary dismemberment of the Ottoman Empire a century ago, the Middle East has been the world’s most recidivist hot-spots for unrest. This might not have mattered and the area’s disputes been a sideshow to major geopolitics, much as the collapse of Spain’s dominion over South America was two centuries ago.
But the disappearance of Turkish rule coincided with the rise of oil as a major fuel powering global economies and the fragility of peace around the Persian Gulf became a matter of constant concern to booming Western economies, dependent on its oil. At first, the British played a lead role, not least because their scattered Empire depended on the Royal Navy and the RN had switched from coal to oil. Saudi Arabia was an ally, Iraq was a Protectorate, Kuwait, Oman and the Gulf States were virtual vassals and the forerunner of BP virtually ran Iran. Post-WW2, growing American global power and an insatiable thirst for oil meant they replaced the British as guarantor of peace in the region.
Not being as adept as the British in local diplomacy, their support for a corrupt Shah prompted the Iranian Revolution and a hostility that lasted the 40 years since. Indirectly, this led to the rise of Saddam in Iraq because his decade-long war with Iran suited US purposes until he over-reached himself, invaded Kuwait and precipitated the two Gulf Wars to clean up the unstable mess, but with mixed results.
Which brings us to today, when Gulf oil that continues to fuel half the world must pass though the Straits of Hormuz to exit the Gulf and reach its markets. US-Iranian were never warm. But, in between debacles like the botched hostage rescue from the US Embassy and the inadvertent shooting down of an Iranian airliner, the forging of an agreement over curbing Iranian nuclear development in exchange or allowing Iranian oil on to world markets had bought a business-like quiet to the region that seemed acceptable to all concerned.

Then Donald Trump became US President.

For reasons he and his advised might understand for internal grandstanding reasons but the rest of the world does not, he pulled the USA out of the nuclear deal, slapped “sanctions” (= a ban on all Iranian oil exports) and precipitated an economic crisis in Iran by removing the main source of income. Whatever you may think of the mullahs’ religion-based regime, this hurts the entire population of 82,801,633 people and fuels a half-century of resentment against Western interference, especially by the USA. Over the last year, sanctions have bitten deeper and driven Iranian reactions to undermine US influence, including support for Hezbollah in Palestine, Assad in Syria and threats to vulnerable tanker traffic in the Gulf.
The Trump-led responses have been inflammatory, to say the least. Recognising Jerusalem as Israel’s capital incensed all Muslims. Declaring Iran’s Revolutionary Guard as a terrorist organisation was insulting. But the most recent moves of a carrier group and 1,000 men to the area is sabre- (sorry, saber-) rattling of the worst sort. Bluff does have its place in global diplomacy. But it only works if it is credible to the other side.
No-one questions the USA as the world’s premier military power and in possession of the world’s most advanced military technologies. But Iran, with 850,000 servicemen (ranked 14th most powerful armed forces in the world) is no pushover, especially with a sanction-resenting population onside. And before anyone cites the “shock and awe” of the Gulf Wars, remember they took over six months to oganise, were backed by a wide coalition (including Arab states) and involved three massive Army Corps, four carrier groups and thousands of aircraft. And even then, though to military victory was overwhelming, the fractious morass in both Iraq and Afghanistan over a decade later underscore that a military victory is just the tip of the iceberg of any full-scale commitment, such as invasion. And such an invasion would be a major undertaking. This is not pint-sized Kuwait. Iran is 1,500km across, covering 1,648,195 sq. km,—nine times the area of Britain and full of mountains.

Any limited “raid to teach Iran a lesson” is likely to run into stiff opposition and incur serious (i.e. unacceptable) losses. Ian has around 170 fighters and strike aircraft, which, although somewhat antiquated, would match a single carrier air group when supported by SAMs. As for 1,000 troops, a battalion-size force would only be capable of a defensive role when faced with 14 divisions (9 battalions each) and 4 brigades (3 battalions each) defending their home turf.

In short, Trump’s sabre-rattling is either insane or only for home consumption. In either case, it is misguided meddling in the world’s tinder-box and lacks the requisite credibility. No wonder the President is rumoured to have been persuaded to back off any military response to the loss of a US drone and to simply keep escorting tankers in and out of the Gulf. He would also be well advised to stop grandstanding and open negotiations with the Iranians before they feel so cornered they have nothing to lose and feel forced do something insane themselves.