Prime Minister Boris Johnson vowed Thursday "to end the era of retreat" as he unveiled Britain's biggest programme of military investment since the end of the Cold War, as the country positions itself for a post-EU future.
The extra spending of £16.5 billion ($22 billion) over four years was welcomed by Donald Trump's outgoing US administration and comes as Johnson bids to build bridges to the incoming presidency of Democrat Joe Biden.
But with Britain's finances under severe strain from the coronavirus pandemic, the government indicated it is likely to raid the legally enshrined budget for overseas aid to pay for other priorities.
The cash boost is intended in part for emerging defence needs such as space and cyber-warfare and Johnson said it showed "our commitment to NATO, the transatlantic alliance and the security of our friends and allies around the world".
"I have done this in the teeth of the pandemic, amid every other demand on our resources, because the defence of the realm and the safety of the British people must come first," he told parliament.
"The international situation is now more perilous and intensely competitive than at any time since the Cold War."
Johnson said the new funding would come to 2.2 percent of British gross domestic product -- exceeding a US-mandated NATO target and more than any European peer -- and was "our chance to end the era of retreat".
Commentators said the prime minister had exempted defence from cost-cutting measures planned to be announced next week by his finance minister, Rishi Sunak, who has splurged more than £200 billion to shore up the economy during this year's pandemic.
The plan was also read as a calculated message to the new Biden administration, harmonising transatlantic priorities on defence after Johnson also put climate change front and centre of his post-pandemic rebuilding policy.
"Which European country has the potential both to project military power and a history of supporting American leadership?" wrote Paul Goodman, a former Tory MP who is editor of the political blog ConservativeHome.
"France has the first but not the second, Germany the second but not the first. Only Britain ticks both boxes," he said.
- 'Threats' -
Britain's military upgrade comes at a pivotal moment for the country.
After formally leaving the European Union in January, it will end the 11-month Brexit transition period at the end of the year and begin a new era in international trade and relations.
Biden will meanwhile take power in late January, with allies hoping his presidency marks a more stable period for NATO after the tumult of the Trump years.
US acting defense secretary Christopher Miller hailed the UK announcement.
"The UK is our most stalwart and capable ally, and this increase in spending is indicative of their commitment to NATO and our shared security," he said in a statement.
"With this increase, the UK military will continue to be one of the finest fighting forces in the world."
Johnson announced a new agency dedicated to military artificial intelligence, the creation of a National Cyber Force and a new "Space Command", capable of launching its first rocket by 2022.
The Space Command follows a similar US force pushed by Trump and is meant to protect British satellites' critical role in modern life, from defence to communications.
Scotland will host the rocket launches and much of a new programme of naval shipbuilding, Johnson said, as he pushes back against a resurgent campaign for independence by the Scottish National Party.
New frigates and other vessels would "restore Britain's position as the foremost naval power in Europe", Johnson said, while "illuminating the benefits of the (UK) union in the white light of the arc welder's torch".
The new programme would create or safeguard "hundreds of thousands of jobs in the defence industry", he added.