The death of Abu Bakr al-Baghdadi this week will not mark the end of the Islamic state, nor US military efforts against Islamist militancy in the Middle East and beyond. But coming against the backdrop of the US withdrawal from Syria and growing Pentagon preoccupation with great-power rivals such as China, it may mark the end of an era in US foreign and military policy.
As late as summer 2014, as IS fighters seized huge swathes of Iraq and Syria, many in the US government still viewed such groups as America's preeminent national security threat and Washington's number one priority. Russia's seizure of Crimea and the beginning of its war in Ukraine the same year, however, were already beginning to shift that focus – a process that has since accelerated.
Even in the Middle East, America's actions and the dynamics of wider conflicts are now defined by great power and other geopolitical factors, with the fight against militant groups – even those that might wish to threaten the West – now simply one of multiple competing priorities.
Where once its planners, arms manufacturers and strategic thinkers were focused on failed states, improvised explosive devices and nation-building, the Pentagon' is now much more focused on hypersonic missiles, cyber, space and potential continental-level wars. Whether the United States will fare any better in these confrontations than its Middle East "forever wars", however, remains an open question.
The defeat of Islamic State and Baghdadi's death point to the paradox of US power since well before September 11, 2001. Throughout that period, the United States has been able to strike and send forces often almost wherever it chooses across a huge swathe of the planet. Its tactics have evolved – sending large numbers of soldiers to Iraq and Afghanistan rarely broke the back of those insurgencies as expected. But through drones, airstrikes, special operations forces and local allies, the United States has been able to push back but never quite defeat its extremist enemies as expected.
It would perhaps be a mistake to say America and its military feel humbled by their experience of the "war on terror". They have become accustomed – and distressed by – frequent attrition and the feeling they have failed to win. But they have also become accustomed to accessing to overwhelming firepower, instantaneous communications coupled with surveillance and intelligence and often friendly local forces. Even when casualties have ratcheted up to thousands over time, they have almost never been taken at the rate of more than a handful in a single day.
That, of course, is very different from the experience of Iraqi, Kurdish and other forces caught up particularly in the brutal early stages of Islamic State's expansion, or events such as the battle to retake Mosul or the Taliban's repeated attacks in Kabul and elsewhere that have often killed more than 100 in a single incident. By one estimate, up to 500,000 people have died in conflicts associated with the "war on terror" – which has cost the US up to $6 trillion in direct and indirect costs.
Those financial costs have dwindled substantially since the withdrawal of major US ground forces. As Turkey's intervention in Syria makes clear, however, the region's wars may if anything get more bloody with the US departure. Russia has made it clear it will willingly provide arms and diplomatic support for brutal governments, and proxy confrontations between Iran and its various nearby enemies continues to intensify. The latter confrontation may yet pull the United States back into the Gulf – albeit unwillingly, given mounting US concerns elsewhere.
Despite concerns over Russia and Europe – as well as Islamist militancy around the world including Africa and Asia – the Pentagon clearly believes the next war it must prepare for most would be in the Pacific. How likely a shooting conflict with Beijing truly is remaining unclear – but if it happened, it could well be the most devastating war the United States has faced since World War Two.
It would certainly be a very different conflict than the United States has become used to. US drones that have operated with impunity for almost two decades would struggle in the face of sophisticated air defences. Some officials openly argue that America's aircraft carriers would be vulnerable to Chinese long-range missile strikes – but others believe that with land bases also likely targeted, America's mobile carrier strike fleets might yet prove amongst its most, not least resilient assets.
The US Marine Corps arguably takes such worries one step further, training to use its short take-off F-35 fighters from tiny islands and atolls, worrying that little else may be able to survive if war should really come. The primary stated the purpose of America's growing military presence is to ensure it doesn't, and that China feels deterred from pushing its growing military footprint too far, for example by moving on Taiwan.
Given its collapsing Mideast clout, particularly with its Kurdish allies, the United States will be glad it killed Baghdadi when it did. But the future is uncertain, and may yet pose more dangers to America and the world that anything Islamic State could ever truly offer.
A former reporter for Reuters, Peter Apps is a writer on international affairs, globalisation, conflict and other issues. He is the founder of the Project for Study of the 21st Century (PS21), a non-national, non-partisan, non-ideological think tank. Paralysed by a war-zone car smash in 2006, he also blogs about his disability and other topics.