LONDON (BLOOMBERG) - The UK completed its divorce from the European Union, leaving the bloc's single market and customs regime more than four years after the country voted for Brexit.
The end of the transition period at 11pm in London on Thursday (Dec 31) launched the UK on a new path on its own, free from EU laws, able to strike trade agreements with other countries around the world, and to reshape its economy at home.
"This is an amazing moment for this country," Prime Minister Boris Johnson said in his New Year's message. "We have our freedom in our hands and it is up to us to make the most of it."
Much, however, remains unknown about what that future will look like after Britain's five decades in the bloc.
Mr Johnson wants to make the UK "a science superpower", pioneering developments in biosciences, artificial intelligence, and battery and wind power technology to create millions of high-skilled jobs for the future.
But how exactly will the UK choose to use its new-found independence from the EU, given the threat of tariffs from the bloc if Britain distorts fair conditions for businesses? Will London or Brussels look to rewrite the terms of the trade agreement, as the accord explicitly allows?
Will Mr Johnson's government be able to secure a vital agreement on financial services, a key part of the British economy? Or will the struggle with the pandemic - and the devastation it is bringing to businesses and jobs - blight his administration's attempts to reform the economy after Brexit?
In the immediate term, practical challenges abound. Mr Johnson's government is braced for disruption at the UK-EU border in January due to companies not being ready to comply with new red tape.
Officials fear queuing trucks will be backed up for miles if businesses don't have the right forms, creating chaos that could disrupt vital supplies of food, chemicals and medicines.
A new trade accord now governs commerce between Britain and the EU, avoiding tariffs and quotas on goods - but adding extra bureaucracy for companies and significantly limiting the ability of businesses to offer services across the bloc.
Yet for Mr Johnson, quitting the EU's structures is a victory for British sovereignty, and the opportunity to "take back control" over lawmaking was always his main argument for Brexit.
The premier has also argued that the finalisation of the EU divorce will settle the question of Europe that has dominated British politics. The vote to leave four years ago has since plunged the government and financial markets into repeated bouts of turmoil, forced out two prime ministers, and seen the UK's relationship with its nearest neighbours ripped up.
Even if the question of EU membership is settled, there is still plenty of room for argument over how close or distant the UK should be to its biggest trading partner. Over the months ahead, Mr Johnson's government has a more pressing emergency - racing to roll out vaccines fast enough to roll back the spread of the coronavirus.
"We know that we have a hard struggle still ahead of us for weeks and months, because we face a new variant of the disease that requires a new vigilance," Mr Johnson said. "But as the sun rises tomorrow on 2021, we have the certainty of those vaccines, pioneered in a UK that is also free to do things differently, and if necessary better, than our friends in the EU."