If Islamic State, as many US and UK officials believe is a significant possibility, did bring down a packed passenger jet over the Sinai desert, then the act would mark a significant escalation of the group’s capabilities and strategic aims, but also underline its continuing regional – rather than global – focus.

One of the key differences between the Isis and al-Qaida, the veteran terrorist organisation it split from, is that it has focussed its energies almost exclusively on seizing and holding territory. Al-Qaida still, theoretically at least, prioritises spectacular strikes on targets in the west.

Al-Qaida has a long track record of targeting planes. This goes back to 1995 and a plot to bring down half a dozen airliners over the Pacific. Then came the 9/11 attacks, a 2002 attempt to bring down an Israeli airliner with a surface to air missile, a hugely ambitious plot in 2006 targetting transatlantic planes and several more recent bids by the Yemen-based affiliate, al-Qaida in the Arabian Peninsula, to strike at western air traffic.

Isis has avoided such operations. One reason is that social media and digital technologies mean it no longer needs a huge spectacular attack killing large numbers of westerners to gain publicity, as was the case when professional news editors or repressive states decided what was broadcast and what was not.

A video of an execution is easily disseminated and provokes shock, horror – and a political reaction – across the globe with only a fraction of the resources of a bigger, mass-casualty strike in the west. A small team of lightly armed gunmen at a hotel or museum in a city somewhere on the Mediterranean shoreline and patronised by Europeans will also gain huge publicity.

So far, Isis has limited itself to calling on individuals in the west to strike targets where they live, rather than directly controlling or commissioning complex attacks anywhere outside the Islamic world. The focus of 99% of the group’s attention has been on its key strategic objectives: slowly but steadily expanding its base in Iraq and Syria, with an accompanying interest in building a network of affiliates.

An attack on Russian passengers in a plane would thus be an escalation, and Isis claims of responsibility for the attack last weekend, though vague, make it clear that Moscow has been added to the members of the “crusader-Zionist alliance” that militants of all stripes believe is dedicated to humiliating, dividing and subordinating the world’s Muslims.

Yet the destruction of the Airbus A321M would be an attack that remains nonetheless within a local context, rather than a global one. The Russians are a target because of their armed intervention in the Syrian civil war from a month ago, not because of their actions outside this theatre.

The prime suspects behind the tragedy, if it does prove to be a terrorist attack, according to reports of the thinking of US and UK officials, are local Isis supporters in the Sinai. The location of the strike is within the core zone of territory most of interest to Isis.

If it was indeed an Isis bomb that brought down the plane – and both Egypt and Russia have downplayed any suggestion that the crash is linked to terrorism – then this still does not signal that the group has launched a fully-fledged global campaign of violence.