Talks between presidents Joe Biden and Vladimir Putin last week over the latter's military intentions in Ukraine have done little to dial down the bellicose rhetoric. Putin has since warned of a "complete rupture" in relations if new sanctions are imposed on Russia, while Biden has assured Ukraine the US will respond very robustly should the Russians invade.
Sanctions under consideration in the West range from cutting Russia off from the system of global financial settlements to imposing new restrictions on Western semiconductors, which Russia needs for its military. There is also likely to be a cut-off of the important Nord Stream 2 gas pipeline.
Whether Putin intends to invade all or part of Ukraine, the US and Nato allies can behave in no other way
Putin's intentions are still no clearer, however. His demands are about restraining potential Nato expansion rather than altering the status quo. While the two leaders' call was by all accounts "constructive", Putin repeated his claims that Russia felt threatened by an encroaching Nato and is demanding treaty guarantees that the alliance will not expand or place nuclear weapons on its borders.
Whether Putin intends to invade all or part of Ukraine, the US and Nato allies can behave in no other way. Russia must see there will be a hefty price for an incursion. And an explicit agreement not to admit further members would be inconceivable; indeed, Russia's threat of military force has revitalised the debate in Finland about whether the formerly neutral country should join. Could Nato agree not to admit it?
Nato is sensitive to the political reality that although it may wish to defend its right to take in new members – whether Ukraine or Finland – it is in practice constrained from what would be portrayed by Russia as extremely destabilising. Its hand is already stayed in the form of the limited support it can provide to Ukraine.
Putin has largely already achieved his aim of stymying further Nato expansion with his troop mobilisation on the Ukraine border. But in the long run his contemptible tactics will most likely only serve to bring Ukraine close to Europe.