Britain's Armed Forces are ready to use 'hard power' against aggressors, Gavin Williamson will declare today.
The Defence Secretary will say it is time to increase our 'lethality' and warn Russia and China there will be a high price for flouting international law.
In a speech in London, he will announce the deployment of the Queen Elizabeth aircraft carrier to the Pacific to deter the Chinese.
He will also talk tough on Russia and pledge to pour further money into boosting cyber defences.
'We have to be ready to show the high price of aggressive behaviour,' Mr Williamson will say.
'To talk but fail to act risks our nation being seen as little more than a paper tiger. Against adversaries upping their spending and advancing technology, we have to respond.
'If we do not, we will find ourselves with fewer options when we face threats in the future.
As uncertainty grows we must be ready to act and bring others with us. Our adversaries are increasingly using cyber-attacks, subversion and information operations to challenge us and the rules-based international order.'
Mr Williamson will urge Nato allies to step up to the challenge of spending 2 per cent of GDP on defence.
He will add: 'The alliance also must develop its ability to handle the kind of provocations that Russia is throwing at us.
'Such action from Russia must come at a cost.'
Setting out the argument for interventionist policies, Mr Williamson will claim actions by China and Russia have blurred the boundaries between peace and war.
The tone of his speech is likely to frustrate Whitehall officials who have urged ministers to play down Russia's strength and not encourage Moscow's propaganda machine.
In his speech, Mr Williamson will fuel speculation about his leadership ambitions with a pitch aimed at Tory Brexiteers.
He will say leaving the European Union gives Britain an 'unparalleled opportunity' to consider how to maximise its influence.
'Brexit has brought us to a great moment in our history,' he will claim. 'A moment when we must strengthen our global presence, enhance our lethality, and increase our mass.
'We shouldn't be shy about our ambition for our forces.'