A 'theory of victory' set out in Warsaw

NATO's top military commander is expected to use a Monday appearance at a security conference in Warsaw to deliver a warning to Moscow over the alliance's capacity to counter any attack, according to officials. US General Alexus Grynkewich, the alliance's Supreme Allied Commander Europe, will use the stage to elaborate his "theory of victory".

NATO has long kept its defence plans secret, and the alliance, founded after World War II to counter the Soviet Union, traditionally does not spell out its military thinking in public. Officials do not expect the speech to reveal new details of strategy. Instead, it is intended both to send a signal to Moscow and to reassure members on the alliance's eastern flank.

The alliance insists it remains a defensive alliance and has no intention of attacking Russia. Colonel Martin O'Donnell, Grynkewich's spokesman, set out the thinking behind the theory of victory last week, saying it is to maintain NATO's advantage, grounded on the alliance's deterrence and defence plans. Given what he called an unsettled global security environment, O'Donnell said: "we need to set conditions now to deter aggression and, if necessary, win if attacked".

The hybrid campaign behind the warning

The warning comes as NATO seeks to tell Moscow to halt what Western officials describe as a "hybrid" campaign of sabotage and interference directed against Ukraine's backers. According to those officials, the attacks have grown more reckless as the Kremlin's forces are stalled in Ukraine, and they risk significant loss of life.

Fears of stepped-up Kremlin action have grown after a series of incidents. These include:

• •the discovery of an explosive-laden drone at a German airport

The alliance has struggled to work out how to cope with incidents in the grey zone beneath open conflict, where such attacks fall.

Reassurance for the eastern flank

Beyond the message to Moscow, the speech is meant to steady NATO members on the eastern flank. NATO Secretary General Mark Rutte has urged countries to keep "calm, carry on and support Ukraine".

Last month, Rutte said: "We should not be naive... about Russia, but they know we are stronger."

US deployment review looms

The reassurance effort comes against an uncertain backdrop within the alliance. European countries are rushing to build up their militaries as doubts have soared over the reliability of the United States under President Donald Trump.

At the same time, allies are bracing for possible cuts to US forces in Europe while the Pentagon reviews its deployments. The results of that process are expected to be announced towards the end of the year.