The Irish Times view on the invasion of Ukraine: A defining test of Western resolve

By moving step-by-step, Vladimir Putin can test just how much he can get away with

Russia's invasion of eastern Ukraine presents Europe and the United States with a defining test. How they choose to respond will determine Vladimir Putin's next move. But it could also set the course of relations between Russia and the West for a generation.

By sending troops into the breakaway Ukrainian regions of Donetsk and Luhansk, Putin has chosen a dramatic escalation – a brazen and illegal invasion of sovereign Ukrainian territory. But the move is not without strategic ambiguity. In the decree signed by Putin after a stage-managed meeting of his security council and an incoherent televised lecture about Ukraine, Russia recognised Donetsk and Luhansk but was careful not to define their borders.

The territory controlled by Russian-armed separatists is less than half of the territory of Donetsk and Luhansk regions. If Russia plans to recognise the entire provinces, including all the land currently controlled by the Ukrainian military, that would raise the threat of a wider war.

Putin knows the West will not respond with direct military force to his aggression in Ukraine – it has decided the risk of nuclear war is too high – but by moving step-by-step he can test just how much he can get away with. The first step was his occupation of part of Georgia in 2008. Then he occupied Crimea and started a war in east Ukraine. He got away with both. In recent months he amassed more than 100,000 troops on Ukraine's borders and moved Russian forces into Belarus in huge numbers only to see a queue of world leaders visit the Kremlin to try to assuage his spurious concerns.

Putin has dropped the pretence: he is openly seeking to renegotiate the end of the cold war, starting with the rolling back of Ukrainian independence

Every signal of weakness in the West’s response will be taken as a green light for further escalatory steps by Putin. That means Europe and the US, when deciding on sanctions, have to strike a balance: measures must be strong enough to punish Putin and deter further aggression but not so crippling that they leave him feeling he has nothing to lose. The United Kingdom’s initial moves are clearly too modest; sanctions on three oligarchs and five relatively small banks are a drop in the ocean from a country that hosts so much dirty money belonging to the Russian elite.

German chancellor Olaf Scholz sent a more encouraging message when he announced the halting of certification for the Nord Stream 2 gas pipeline. That will come with a heavy price for Germany. But there is far more at stake in this crisis. Putin has dropped the pretence: he is openly seeking to renegotiate the end of the cold war, starting with the rolling back of Ukrainian independence. For Berlin and for every other capital, the financial hit incurred at home by choking off trade with Russia is a price worth paying for the greater goals of saving Ukraine, defending democracy and averting war in Europe.