Britain's Prime Minister Theresa May speaks at the Conservative Party's Spring Forum in Cardiff, Wales, March 17, 2017. [Photo/Agencies]

On Wednesday, the United Kingdom formally launched the process for it to leave the European Union, with Prime Minister Theresa May triggering Article 50 of the Lisbon Treaty, which opens a two-year window for negotiations on it leaving the bloc.

Though May has promised to "make a success" of the divorce, there are many uncertainties and restraints that are likely to undermine her efforts to achieve that goal.

Internally, she is facing a highly disunited nation, especially as Scotland, in a bid to hold on to EU membership, is seeking a new referendum on independence.

Externally, there is the possibility that negotiations will break down and the UK will be forced out of the EU without any deal in place. Whatever the outcome, it will need to secure new trade agreements with European partners and seek alternative markets. Neither of which is likely to be easy.

The latter because it previously positioned itself as a stepping stone to the EU, and without that it will need to find new selling points.

China, for instance, regarded the UK as a bridge to tap the vast market of the EU, its largest trading partner.

Sino-UK cooperation will continue, however. The UK, China's second-largest trading partner among EU members, has always sought Chinese investment in such fields as nuclear power and high-speed rail; while China has looked to the UK for help in developing its financial market and facilitating the process of the yuan's internationalization. London has already become a main hub for the offshore trading of the Chinese currency.

And, as a founding member of the China-led Asian Infrastructure Investment Bank, the UK can realize opportunities from the bank's financing of massive infrastructure projects across Asia, Africa and Europe.

Also, both China and the UK are advocates of free trade. While talks on the signing of a free trade agreement between China and the EU have been extremely slow, because of pressure from some EU countries, Brexit may propel China and the UK to reach an FTA deal at an early date.

The future of Sino-UK collaboration in the post-Brexit era, thus, rests on the vision and statesmanship of their leaders.

And while Brexit reflects the tendency of some countries to look inward and backward, China's leaders continue to look outward and forward, championing the view that economic globalization, not isolation, is the right way forward, and countries should seek common benefits.