IT'S been called a war of words, but for a long time now it's been so much more than that.

The assassination of nuclear scientists, exploding missile sites, mysterious plane crashes, disappearances, sophisticated cyberwarfare and worldwide bomb attacks; all have become the hallmarks of the bitter ongoing covert war between Israel and its United States ally on one side and Iran on the other.

The two camps have for years of course been implacable foes, but the heightened tensions over Tehran's nuclear programme and most recently the string of assassination attempts on Israeli diplomats, in India, Georgia and Thailand, have once again brought this clandestine war out of the shadows.

Whether it be the use of sticky bombs attached to cars and detonated to kill prominent Iranian nuclear experts or the Stuxnet computer worm that targeted the industrial software vital to Iran's uranium enrichment efforts, there can be no more obvious explanation for such events than that Israel's Mossad intelligence service and the CIA – possibly working in collaboration – are pulling out all the stops to neutralise Iran's nuclear ambitions.

While it would be foolish to talk of winners or losers in such a confrontation, there is no escaping the fact that Israel and its Western allies appear, so far, to have had the upper hand in this secretive, no-rules war.

While the strikes against Iranian targets have consistently been sophisticated and slickly carried out, the response in terms of the attacks on Israeli envoys has been ham-fisted and focused on comparatively "soft" targets. This is where things don't quite stack up as they should.

Time and again Western security analysts have made the point that the Iranian Revolutionary Guards are a highly trained and tactically savvy outfit.

Should Iran indeed be behind the latest terrorist strikes against Israeli envoys, why then have they been so amateurish in their execution?

According to the US global security think-tank Stratfor, it's perhaps because Tehran may not have been "employing its most capable assets". In other words the Iranian secret service may have put the assassination operation out as contract work, allowing President Mahmoud Ahmadinejad's regime convenient deniability.

Should that theory be substantiated, then Iran's Lebanese ally, the militant group and political party Hezbollah, would be the most likely candidate.

For Hezbollah, the Israel Defence Forces (IDF) representative in Delhi would be an attractive target, given Israel and India have become close military allies and the Indians are now Israel's largest export market for arms.

Significantly too is the fact the latest terrorist attacks came almost four years after the head of Hezbollah's armed wing, Imad Mughniyah, was killed in a car bomb in Damascus in an operation the group always insisted was the work of Mossad.

While Mughniyah had been attacking Israeli targets since 1982, following his killing Hezbollah always promised to seek revenge – and Israel has braced itself every anniversary since his death.

Should Hezbollah, or indeed some other Islamic militant or jihadist group, prove to have been contracted by Iran to carry out the operations in Delhi, Tbilisi or Bangkok, then their fairly ineffective deployment as armed proxies on foreign territory stands in marked contrast to what some sources say is Mossad's use of dissident Iranian group the Mujahedin-e Khalq to target nuclear scientists, security personnel and facilities inside the Islamic Republic itself.

Time and again such clandestine activities and sabotage have struck at the very heart of the Iranian military and industrial establishment.

The problem with all these shadowy spy wars of course, is how easily they can get out of hand, creating the spark for a real, open season shooting war. Indeed Middle East history is littered with similar past conflicts that flared up for much the same reasons, including the 1982 Israeli Army invasion of Lebanon, conducted partly in response to a terror attack on the Israeli ambassador in London.

As if all this ratcheting up of a covert war over Iran's nuclear programme wasn't bad enough, there are other worrying signs of where it all might lead.

Largely under the media radar on the beaches and grounds of Camp LeJeune, a sprawling US Marine Corps base in North Carolina, a large-scale amphibious military exercise codenamed Operation Bold Alligator has been under way over the last few weeks.

This 11-nation "war game" involving 20,000 troops on the shoreline of a fictitious Middle Eastern country that strangely enough happens to resemble Iran comes as tension continues in the Strait of Hormuz, through which 40% of the world's seaborne oil trade passes and which Tehran has threatened to blockade in response to international pressure over its nuclear programme.

A few days ago Iranian TV claimed the country would stop exporting oil to a number of EU countries, helping drive the price of crude to nearly $102 a barrel and, in the long run, hitting western consumers at the petrol pump.

So there we have it, a sharp escalation in an increasingly bloody spy war over a nuclear weapons programme, large-scale military exercises in the US and tensions over the availability and price of Middle East oil. All this of course may yet come to nothing, but it would be naive to ignore the potentially combustible mix they could point towards.