NATO faces 'new era' of threat as Moscow prepares 'grey zone' strike against Poland

MOSCOW is preparing a “grey zone” attack on Poland before Christmas, a senior Russian military official has revealed.

- By Marco Giannangeli

The warning, sent through an Eastern European ally during London’s DSEI arms fair last week, has triggered urgent discussions in the UK and US about the risk of a deniable strike aimed at fracturing NATO.

It comes as Russia continues a new tactic to pressure NATO by sniping at its borders to test the alliance's resolve.

In the latest case, three MiG-31 fighter jets capable of carrying hypersonic missiles breached Estonian airspace. The Russian jets were intercepted after circling for 12 minutes over the Gulf of Finland.

Estonian Prime Minister Kristen Michal described the incident as “unprecedentedly brazen”, while Donald Trump warned it could cause “big trouble”.

Foreign Secretary Yvette Cooper said: “The UK stands with our Estonian allies, following yet another reckless incursion into NATO airspace by Russia. We must continue to increase pressure on Putin, including driving forward the new sanctions announced by the UK and the EU.”

But while NATO’s northern flank has been repeatedly tested, the Russian military official warned that Poland could face something far more direct.