Outside of the intense war zones of Iraq, Syria and Afghanistan, this week’s devastating bombings in Sri Lanka are the deadliest terror attacks since 9/11, with 359 people killed and more than five hundred injured. The Sri Lanka attacks are part of a wider pattern that has direct parallels with the aftermath of 9/11 and are proof, if any was still needed, that the al-Qaida/ISIS phenomenon is very much with us. Eighteen years of the “war on terror” has achieved little except to see hundreds of thousands of people killed and injured and millions displaced from their homes.

Devastating though these new attacks are, they have overshadowed another development that looks at first sight to be of no consequence but, in its way, is just as telling. Last Thursday ISIS claimed responsibility through its Amaq News outlet for an attack on Congolese soldiers near the village of Kamango close to the Uganda/Congo border. The attack killed and injured government troops and was part of a two decade-long rebellion against the government by a group formerly known as ADF (Allied Democratic Forces) that draws much of its support from among the DRC’s Islamic minority which is mainly in the north and east of the country.

This incident is significant in two ways. First, ADF last year rebranded itself as Madinat al Tawhid wal Muwahedeen (the city of Monotheism and Monotheists – MTM), a transformation that was cited by the ISIS leader, Baghdadi, in a video last August. Secondly, the recent attack was the first to be claimed by ISIS itself. While the real extent of the connection with ADF/MTM is not clear, even a year ago Congolese troops found extensive evidence of links when they raided a rebel camp, and other sources link the group with financial support from ISIS itself.

ADF/MTM is part of an expansion of Islamist paramilitary movements across the Saharan Sahel region now down into Central Africa, variously linked to al-Qaida and ISIS, as covered in a recent Open Democracy column and more extensively in a briefing from the Oxford Research Group. The ORG analysis also highlighted the continuing ISIS links to the Islamist paramilitaries in the southern Philippines and their five-month assault and occupation of the city of Marawi which left over a thousand dead, tens of thousands displaced and a large parts of the city wrecked.

It is part of a wider pattern which has also involved attacks in the UK, France, Spain, Germany, Turkey and the United States, some carried out by individuals acting alone, others more clearly connected to ISIS.

What seems to be forgotten is that we have been here before.

After 9/11, the US-led war in Afghanistan seemed spectacularly successful in terminating the Taliban regime in Afghanistan and wrecking al-Qaida. President Bush was able to celebrate the victory in his January 2002 State of the Union address, and extended the war to a world-wide operation against the “axis of evil” of Iraq, Iran and North Korea.

Almost at once, though, paramilitary attacks started against western and Israeli targets in many countries. Best remembered is the Sari Club bombing in Bali and the multiple attacks in London and Madrid, but there were scores of others. They included quadruple attacks in Casablanca and Istanbul, the former against western-linked targets and the latter against two historic synagogues, the HSBC bank and the British Consulate. Three international hotels in Amman were bombed, as were Marriott hotels in Islamabad and Djakarta and Israel-linked hotels in Sinai and Kenya.

As with recent ISIS-inspired attacks, some were by individuals, others by groups. Some were just inspired by al-Qaida and Osama bin Laden, and others had much closer connections. Overall they lasted more than three years before being side-lined by the war in Iraq as thousands of young men went to join that cause.

The precise details of the movement that caused the carnage in Sri Lanka are not easy to decipher, not least because of the political divisions within the Sri Lankan government and an intense blame game now under way, but it appears to have been a detailed, sophisticated and long-planned operation which goes well beyond being “inspired” by ISIS. Indeed the indications that some of the bombers were highly educated and had worked and studied abroad, are uncomfortably close to the make-up Frankfurt Cell that was at the root of 9/11.

Although the long-term significance of the 2002-05 attacks was largely missed at the time, there are elements which are relevant to both recent developments and likely future trends. By 2005 al-Qaida was establishing itself in Iraq in a direct and potentially devastating war zone which was to last until 2008 before slowly subsiding. For Obama’s incoming administration, prospects for Iraq looked reasonable and almost all the US troops were withdrawn by the end of 2011.

But a new movement arose from the remains of al-Qaida in Iraq. It linked up with extreme Islamists in Syria and ISIS was born. With the emphasis on a physical Caliphate it made rapid progress until it met with a devastating US-led air campaign that started in 2014 and continued for nearly four years. During that time, the ISIS leadership began to plan for the eventual demise of the Caliphate, encouraging many of the attacks across Western Europe while also making links across northern Africa, in Afghanistan, the Philippines, Indonesia, Bangladesh and, as we now know, Sri Lanka.

What is now uncomfortably clear to some western military analysts is a dual predicament. The extraordinarily intense air war, which has killed over 60,000 ISIS supporters and thousands of civilians in Iraq ands Syria, has not destroyed ISIS – it has been another failure in the long war. But also, there is a difference between the 2002-05 spate of attacks and the current situation. The earlier attacks may have been inspired by bin-Laden, Zawahiri and others, but they were hardly systematic and often depended on near-random local grievances. This time, though, the operations in the Philippines and now in Sri Lanka point to a more substantial and centrally organised programme.

If that turns out to be the case, and with little prospect that western military responses will make much difference, we might at last get to the point where the war on terror is seen to be unwinnable and quite different approaches will at last have to be tried.