The Ministry of Defence says the integrated policy review will assess the UK's "place in the world" and dictate future changes to procurement and international relations.
Experts have now offered their insight, welcoming a review that could elevate the UK's global position.
James Sullivan, the group's Head of Cyber Research, says the UK must "capitalise more effectively" on its world-class cyber security.
"It should make the UK’s leading role in cyber security a core part of its position in the world," he said.
What has been described he deepest review of British foreign, defence and security policy in 30 years, will offer conclusions by the end of the year, while remaining committed to NATO's target of member nations putting 2% of GDP towards defence.
Defence spending in the alliance has been the target of criticism from US President Donald Trump, who has suggested other members should be contributing more.
Professor Malcolm Chalmers, RUSI Deputy Director-General, welcomes a foreign policy grounded in home interests, adding international doctrines like Mr Trump's 'America First' policy could leave the UK "isolated".
Neil Melvin, Director of the International Security Studies Research Group, says that the review should encompass a forward-facing approach to international security.
"A central task of the review will be to determine the UK’s strategic approach to Russia and China, notably regarding their security activities in these key regions," he said.
Balancing economic relations with other nations against the threats they pose, Mr Melvin says the UK should aim to steer hostile countries "into more cooperative and less confrontational relationships".
The integrated review will report to the Prime Minister, who will be supported by a cross-Whitehall team in the Cabinet Office and a small team in Downing Street - comprised of experts from inside and outside the Civil Service.
Departments across Whitehall will contribute to the review, including the MOD. Decisions will be made by the National Security Council, chaired by Mr Johnson.
Professor Peter Roberts, Director of RUSI's Military Sciences Research Group, says the biggest question facing the UK is which role it wants to play in "an era of great power competition".
"It needs to decide whether the UK wishes to be an active participant in shaping a new order or focus on preserving existing arrangements against the tide of change," he said.
"This should address the circumstances under which the UK will act, including militarily, to protect its interests."