Europe could be next on al-Shabaab's hit list

Some of the chaos and bloodshed of everyday life on the streets of Mogadishu was visited on the Ugandan capital on Sunday night. As the bodies of innocents ripped apart while they watched the World Cup final are buried and the burnt remains are sifted there is a keener sense of the cost of ignoring the world's most failed state.

That Kampala should be forced to pay the first instalment of that cost is bitterly unfair. The real responsibility for the emergence of al-Shabaab and the seemingly endless war in Somalia is more widely held and more complex. Should the twin bombings in the Ugandan capital be confirmed as the work of Somalia's largest Islamic militant group, then the logic and timing behind the attack is clear.

The World Cup offered a point of maximum publicity and poignancy for al-Shabaab to hit out at the country that is doing more than any other to maintain Somalia's weak transitional government. Uganda provides the bulk of a small African Union force – augmented by troops from Burundi – that is the last line of defence against al-Shabaab's stated aim of taking over the capital, Mogadishu.

The atrocity would also open a new phase in which al-Shabaab, which claims allegiance to al-Qa'ida, begins operations in foreign countries. This would have profound implications for cities from Cape Town and Nairobi to London and Minnesota where a large Somali diaspora would find itself viewed as a potential source of terrorism. The timing of Sunday's attack would also seem designed to intimidate would-be contributors to the AU force that was set to grow from 2,000 to 5,000 soldiers. The leadership of al-Shabaab has repeatedly threatened to strike Uganda and Burundi at home, and threatened other neighbours such as Kenya with retribution on its own soil.

Another aspect of the militants' anger at Uganda is the country's hosting of a European Union-supported military base at Bihanga in the west of the country where 400 Somali government soldiers are being trained by a mix of Finnish, Irish, Portuguese and French army instructors. This is the first phase of a long-delayed programme to build-up the forces of the government of Sheikh Sharif Sheik Ahmed in Somalia.

The most ominous aspect of the huge loss of life in Kampala is the possibility of a shifting balance within an Islamic movement which has until now been parochial in its aims.

The group was originally the youth wing of the Islamic Courts Union, a bold local experiment in unseating rival warlords and a corrupt transitional government in 2006 that was ended by a US-backed Ethiopian invasion. That foreign intervention helped to turn the movement into a radical Islamic army, swollen by the tens of thousands of young and disaffected Somalis with few other options in the shattered state.

Al-Shabaab was fighting a holy war against a government which it viewed as insufficiently Islamic and a proxy for outsiders. Until now, its operations had largely been confined to central and southern Somalia where it has succeeded in asserting dominance and imposing its own extremist form of Islamic law.

However, there have long been tensions between the nationalist elements of al-Shabaab and the internationalists who have joined their ranks – many of them foreign fighters. The al-Qa'ida wing of the movement has placed its struggle in the context of a global Jihad and made repeated threats to foreign targets.

"A conference of those two strands within Shabaab happens when you attack Kampala," said Roger Middleton, a Somalia analyst with think-tank Chatham House. "It's really worrying because the thing about this for a long time is that people have been saying Shabaab is primarily concerned with what is going on inside Somalia and they're fighting inside Somalia."

For the last 18 months Western intelligence agencies have been warning of a mounting threat from al-Shabaab which can take cover among the hundreds of thousands of Somalis who make up the global disapora.

The reverberations of the war in the Horn of Africa reached Melbourne in Australia this time last year after a huge security operation led to the arrest of four Somali men allegedly linked to an al-Shabaab plot.

As investigators sift the wreckage of the two bomb sites in Kampala, governments around the world will be scrambling to prevent the potential threat of similar scenes in their own cities. They will also be confronted with the dilemma of disengaging further from the anarchy many of them are complicit in creating in Somalia or charting a fresh and more constructive engagement with a country some had decided they could afford to ignore.