James Rogers, founding member of The Henry Jackson Society and the Director of Global Britain Programme, said increased defence spending will help underpin European security.
He called for Britain to increase spending to at least three per cent of its GDP over five years.
Speaking exclusively to Express.co.uk, Mr Rogers said: “The UK is a European power, an underwriter of NATO, and thus European security, but it also has a global perspective.
“Defence spending should be increased to at least 3% of GDP, albeit gradually, over a five-year period.
In 2016 Britain was ranked seventh in a league-table of defence spending after – US, China, Russia, Saudi Arabia, India and France.
Mr Rogers said the extra cash should be spent on more troops and better technology to help NATO.
He said: “The UK needs to ensure it has a larger army to underpin its commitments to the Eastern flank of NATO, where it already has sizeable ‘tripwires’ garrisoned to prevent Russian miscalculation.
”Cyber capabilities are critical, but so are direct-energy weapons, which could revolutionise warfare in the same way as gunpowder did in the fifteenth and sixteenth centuries.”
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