(The opinions expressed here are those of the author, a columnist for Reuters)

LONDON - As Afghanistan's Taliban celebrated the first anniversary of their seizure of Kabul, supporters took to Twitter to commemorate their suicide bombers, using the hashtag "martyrdom seekers" and posting dozens of videos of attacks and explosions.

"We love being killed in the path of Allah as much as you love your life," wrote pro-Taliban user Ajmal Mansour. "We have not only made sacrifices for the formation of an (Islamic government) but we are always ready to preserve it."

For almost 20 years, the United States, Britain and their NATO allies ploughed troops and more than $1 trillion into Afghanistan, only to see the security structures they had built unravel almost overnight. Paying the price are ordinary Afghans, whose country changed beyond recognition during the NATO presence but now faces a very different future.

The lessons of last year's rout, however, go well beyond Afghanistan. Occasional awkward discussions of "lessons learnt" aside, the national security establishments of Washington and its allies have refocused hard, driven by Russia's Feb. 24 invasion of Ukraine and mounting tensions over self-ruled Taiwan, which China claims as its own.

At their June summit in Madrid, NATO leaders recommitted themselves to the defence of their Eastern members with a dramatic increase in troop numbers all along the border with Russia and Belarus, with U.S. President Joe Biden declaring the alliance's Article 5 self-defence clause a "sacred obligation" – but with scant reference to its just-ended longest war.

Events last year in Kabul have had their own effect upon these larger, newer confrontations.

China has repeatedly warned Taiwan that the lesson of Afghanistan is that it too will be abandoned. Russia pushed a similar line before it moved against Ukraine – while U.S. intelligence agencies briefed eerily similar warnings of imminent collapse and Western governments again raced to evacuate their embassies.

Such scenes gave Beijing and Moscow a strong narrative to push – that what happened first over two decades and then again last summer in Afghanistan points to deep-seated and catastrophic weaknesses in Western democracies, coupled to an unwillingness to face facts and callous disregard in leaving allies in the lurch.

AFGHAN COLLAPSE, UKRAINIAN DEFIANCE

Last Wednesday, Chinese Foreign Ministry spokesperson Wang Wenbin called for the United States to learn from its "failure" in Afghanistan, while Russia pointedly welcomed an Afghan trade delegation to Moscow.

Neither China or Russia has yet to recognise the Islamist group as the true government of Afghanistan. But while they both unambiguously relished Western defeat, they highlighted the anniversary less aggressively that they might have.

In part, that is likely due to the complicating effect of the conflict in Ukraine, itself six months old next week. To what extent events in Kabul helped persuade Russian President Vladimir Putin that the Ukrainian government would collapse similarly quickly is hard to gauge, but Ukraine's resilience has shifted expectations of the willingness of Western democracies to adapt, fight and innovate when they are truly threatened.

Former U.S. defence official Anthony Cordesman - now chair of strategy at the Center for Strategic and International Studies in Washington – argued in a report this month that U.S. Afghan strategy was initially conceived in a fit of emotion after the Sept. 11, 2001, attacks and then never truly coalesced into something achievable.

Similar concerns were expressed and repeatedly ignored throughout the NATO intervention, which ceased major combat operations at the end of 2014 – and although a training mission remained until last summer, the alliance was already refocusing its attention on Russia after Putin's initial 2014 escalation of conflict with Ukraine.

Even at the height of NATO combat operations between 2006-13, eastern European nations were often relatively blunt that the reason for their presence was to build goodwill with allies for when the Russian threat returned.

U.S. DRONE STRIKE

At the start of Russia's invasion of Ukraine, NATO's eastern members expressed concerns that the U.S., Britain and the alliance might prove similarly slipshod when it comes to building out NATO's new "strategic concept", particularly ensuring sufficient logistics, ammunition and command were in place to fight Russian forces if needed.

For Afghans, of course, such admissions deepen the feeling of betrayal and waste as they struggle with drought, food shortages, financial crisis and a government not yet internationally endorsed by its closest allies in Pakistan. Both Moscow and Beijing, meanwhile, have their own worries about Afghanistan's new Taliban rulers.

Earlier this month, a U.S. drone strike in Kabul killed al Qaeda leader Ayman al-Zawahiri, a reminder of the U.S. ability to reach its enemies without resorting to colossally expensive military interventions – but also that its initial goal, to chase militancy from Afghanistan, had proved a failure.

In comments to mark the anniversary of the fall of Kabul, the Taliban's foreign affairs ministry pledged again to ensure that no attacks would be launched from its territory against any foreign state, saying it had intercepted and stopped an attempt to fire rockets into neighbouring Uzbekistan.

But Zawahiri's death, and the fact that he appeared to be living in a Kabul suburb favoured by Taliban leaders, have repeatedly been described even within the relatively self-censoring Afghan media as a "disaster" and "embarrassment".

It is a reminder of several awkward truths. Neither the U.S. and its allies nor the Taliban have worked out how to deal with the unexpected speed and reality of last summer. But all will need to if they wish to avoid being overwhelmed by a similarly savage collapse of wishful thinking in the future.

** Peter Apps is a writer on international affairs, globalisation, conflict and other issues. He is the founder and executive director 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 crash in 2006, he also blogs about his disability and other topics. He was previously a reporter for Reuters and continues to be paid by Thomson Reuters. Since 2016, he has been a member of the British Army Reserve and the UK Labour Party.

(Editing by Nick Macfie)