Instability is growing, Putin’s hybrid war in Europe is heating up and for fear of escalation we have encouraged global nuclear proliferation

There are human activities in which both sides can win. War is not one of them. Either Ukraine wins this war or Russia does. Ukraine’s former foreign minister Dmytro Kuleba says bluntly that unless the current trajectory is changed, “we will lose this war”.

To be clear: this is still avoidable. Suppose the roughly four-fifths of Ukrainian territory still controlled by Kyiv gets military commitments from the west strong enough to deter any further Russian advances, secure large-scale investment in economic reconstruction, encourage Ukrainians to return from abroad to rebuild their country, and allow for stable, pro-European politics and reform. In five years, the country joins the EU, and then, under a new US administration, starts the process of entering Nato. Most of Ukraine becomes a sovereign, independent, free country, firmly anchored in the west.

Timothy Garton Ash is a Guardian columnist