Extra defence spending including the creation of two new rapid-reaction "strike brigades" will help give the UK the ability to "shape" world events, David Cameron claimed.
The Prime Minister will give details of an additional £12 billion of equipment funding when he sets out the Government\\\\\\\'s National Security Strategy and Strategic Defence and Security Review (SDSR) in the Commons.
He will also announce a 10-year extension to the operational lifespan of the RAF\\\\\\\'s Typhoon jets and upgrade work to give them ground attack capabilities - effectively adding two additional frontline squadrons.
But unions are braced for the SDSR to include plans to slash thousands of civilian Ministry of Defence (MoD) posts to cut costs.
Defence spending received a boost in the Budget, when George Osborne, under intense pressure from MPs and defence chiefs, declared that the UK would continue to meet a Nato target to devote at least 2% of national wealth to defence.
Mr Cameron said the UK was the only major country to meet both its Nato commitment and an obligation to spend 0.7% of national income on aid - and was doing both due to "clear-eyed self interest".
Speaking at RAF Northolt ahead of his Commons statement, the Prime Minister said: "This is showing that there is no economic security without national security and vice versa.
"We have now got a stronger economy and we can choose, rightly, to invest more in our national security - more ships, more planes, a bigger navy, a bigger RAF, a better equipped army, better in terms of fighting cyber attacks and fighting terrorism.
"Britain is the only major country anywhere in the world that both meets its Nato spending targets and meets its aid commitments.
"We are an engaged nation, not for reasons of national vanity but for reasons of clear-eyed self interest. What goes on in the world matters to the United Kingdom and so we should be helping to shape it.
"And with today\\\\\\\'s announcement we can do just that."
The Chancellor revealed yesterday that the purchase of new F35 Joint Strike Fighter aircraft for the Royal Navy\\\\\\\'s two new aircraft carriers would be accelerated - making 24 available by 2023 rather than the previously planned eight.
It has already been announced that the SAS and other special forces will get an extra £2 billion to improve their equipment, the RAF will double its number of drones, an extra £1.9 billion will be spent on cyber security and 1,900 new spies recruited.
The SDSR is also expected to reveal that the expected cost of renewing the UK\\\\\\\'s nuclear deterrent has risen - with the SNP warning against cutting the number of anti-submarine frigates to be built in Scotland to compensate.
Boeing has won an industry bidding war to provide nine P8 aircraft to plug the gap left by the highly-criticised decision in the last review in 2010 to scrap a new generation of Nimrod aircraft.
Defence chiefs were forced to call in help from the France, the US and Canada to track a suspected Russian submarine off the coast of Scotland last year amid warnings the lack of patrols was allowing Moscow to spy on the UK\\\\\\\'s nuclear deterrent.
The American manufacturer had been considered the favourite as Royal Air Force crews are currently serving on P8 Poseidons with the US military to maintain skills.
Officials claim the P8s offer maritime surveillance, anti-submarine and anti-surface ship warfare capability, increasing further the protection of Britain\\\\\\\'s nuclear submarines and new aircraft carriers. They will also provide maritime search and rescue and surveillance capabilities over land.
These roles require an aircraft that can carry torpedoes, as well as being fitted with a broad range of sensors, including radar and sonobuoys.
The new 5,000-strong strike brigades would be equipped to deploy across the globe and would use the Army\\\\\\\'s new generation of Ajax armoured vehicles.
The Typhoons will now see service through to 2040 to answer RAF fears over the dwindling size of its resources - with the extended lifespan meaning there will be seven squadrons of around 12 aircraft.
As well as being enhanced to add ground attack capability to their aerial combat role, they will be fitted with upgraded stealth radar equipment.
Mr Cameron, who will return to Parliament later in the week to make the case for air strikes against Islamic State in Syria, said the strategy was based around "an understanding that we cannot choose between conventional defences against state-based threats and the need to counter threats that do not recognise national borders".
In the foreword to the SDSR he wrote: "From the rise of Isil and greater instability in the Middle East, to the crisis in Ukraine, the threat of cyber attacks and the risk of pandemics, the world is more dangerous and uncertain today than five years ago."