Was this the week Ukraine lost the war? Or to put it another way, the week the west lost Ukraine? Heroic battlefield resistance continued, Ukrainian citizens struggled on in the teeth of pitiless atrocities such as the missile strike on Kyiv’s Okhmatdyt children’s hospital – but in Washington, risk-averse Nato leaders stuck stubbornly to a route map to defeat. Ultra-cautious US president Joe Biden, whose political weakness grows by the day, says the 32-country alliance is the strongest the world has ever seen. But what use is an alliance that is afraid of a fight? Rarely has the gap between the rhetoric of solidarity and a dismaying political refusal to directly confront Russian brutality yawned so wide. This chasm may prove fatal to Ukraine and Nato. Alliance chiefs agree that repulsing Moscow is vital for Europe’s future security and the rule of international law. But their new “Ukraine Compact” helps Kyiv to merely survive, not win. They have no plan for victory over Russia. Indeed, they seem to fear it. That’s an open invitation to President Vladimir Putin for renewed aggression in eastern Europe. Nato’s latest allocation included some air defence systems, planes and cash. It offered Ukraine a “bridge” to “irreversible” membership, which, if the US and Germany prevail, may never happen. Following the dismal pattern of the past two years, it was too little, too late – and it won’t stop Moscow’s smirking war criminal-in-chief. “When the dust settles after all the motorcades leave Washington, there will be the same uncertainty in Ukraine as before the summit,” wrote the former US Nato ambassador Kurt Volker. “Brutal fighting on the frontline, daily Russian bomb and drone attacks against Ukrainian civilians and infrastructure [and] a Putin who believes he can still win.” Volker warned that, despite the 75th anniversary summit’s self-congratulations, “fundamental questions about the future of war and peace in Europe will remain unanswered”. As repeatedly urged here, he said Nato should enforce a defensive air umbrella over western and south-western Ukraine and fast-track its Nato and EU membership. Keir Starmer said Ukraine can still use UK-made Storm Shadow missiles to attack Russian territory “for defensive purposes”. But Biden still refuses to allow Kyiv to strike the missile and bomber bases deep inside Russia that are used to launch attacks such as that on Okhmatdyt hospital. Restrictions also apply to newly supplied F-16 fighters. Biden’s personal health and age problems, dramatised by last week’s excruciating press conference gaffes, were an unfortunate distraction at a summit intended to project western unity and prowess. Amid an escalating political and media firestorm over his fitness to run again, Nato’s nemesis, Donald Trump, lurks ominously in the shadows. Mark Rutte, the former Dutch prime minister, was selected as next Nato secretary general partly for his ability to get on with Trump. But no amount of male bonding and flattery obscures the fact the Republican candidate is a Putin fan who plans to dictate a “peace” settlement to Ukraine. Should Trump return – and there’s a growing chance he will – it’s entirely possible that Nato’s “irreversible” promises will be binned, US bilateral aid will cease, Putin will be rewarded for aggression with permanent territorial gains and “delinquent” Europeans, as Trump termed America’s allies last week, will again be threatened with withdrawal of American protection. There was more bad news for Ukraine last week from France. President Emmanuel Macron, a champion of Kyiv’s cause and impassioned advocate of shared European defence, is on the back foot following his party’s losses in parliamentary elections. Macron is widely described as weakened, even as a lame duck. But much of this analysis comes from commentators who wrongly predicted a far-right victory. Macron deserves credit for demonstrating that Europe’s rising tide of intolerant nationalist-populism can be turned back. His determination to vanquish Putin’s Russia, which he views as a mortal threat, is not shared by Germany’s chancellor, Olaf Scholz, the other big EU player. Overly fearful of nuclear escalation, he has been the ultimate Ukraine foot-dragger – and he stuck to his (spiked) guns and slashed defence budget in Washington. Epitaph for Scholz: he understood the 2022 invasion marked a historic watershed – a Zeitenwende – then failed to rise to the challenge. Nato and the west face some other potentially existential problems. The alliance has yet to convincingly define its role in the post-Soviet era. The Balkans in the late 1990s was a mess, Afghanistan was a disaster. Members argue over Gaza as well as Ukraine. And now there’s China, whose covert military support for Putin’s war was singled out for censure. “The most obvious source of strain [within Nato] is the shifting distribution of world power,” argued Harvard professor Stephen Walt. “China has emerged as… a formidable challenger. Asia’s share of the world economy (54%) is substantially larger than Europe’s (17%)… Asia rightly commands a greater share of US attention today, and Europe rightly merits less.” As a result, he said, transatlantic allies were gradually drifting apart. Efforts to give Nato, as opposed to the US alone, a larger role in the Indo-Pacific have limited scope. Notwithstanding Britain’s half-baked “tilt to Asia” under the Conservatives, “Nato’s European members couldn’t do much to affect the balance of power in Asia even if they wanted to,” Walt wrote. Instead of casting around for fresh global challenges and missions, Nato should concentrate on proactively confronting the supremely dangerous threat on Europe’s eastern borders. It’s the same menace that prompted the alliance’s founding in 1949. Russia remains Nato’s raison d’être. It always was. Deterrence is not enough. Putin must be unambiguously defeated and he and his murderous generals brought to trial. The alternative – the loss of Ukraine – may sound a death knell for Nato itself. Simon Tisdall is the Observer’s Foreign Affairs Commentator