Editor’s Note: Ian Bremmer is president of Eurasia Group and GZERO Media. The opinions expressed in this commentary are his own.

Leave aside the particulars of this month’s Brexit drama — Theresa May’s dance moves, Boris Johnson’s attacks on May’s plan, and the latest warnings from European capitals — it’s time to brace for Brexit. Let’s focus on the few geopolitical certainties we know will follow the UK’s exit from the European Union, on whatever terms it comes.

Start across the Atlantic. Brexit won’t do the “special relationship” between the US and Europe any favors. An EU without the UK is a much weaker partner for Washington when US-EU interests align and a much weaker foil when those interests collide.

Yes, many of the issues currently dividing the US from Europe have been a long time coming — differences over Russia policy, NATO funding and Middle East adventurism have strained US-European relations before. But Brexit undermines the transatlantic alliance across the board because Brexit challenges will divert Brussels’ overall energy and attention away from working with Washington to help bridge their divides.

The UK will be weaker, as well, in a post-Brexit world. It will need its partnership with the US more than ever, especially as London’s standing as a global banking center diminishes. If there’s one person who understands leverage, it’s US President Donald Trump, who will have a lot more negotiating leverage with the UK when it comes time to negotiate a one-on-one trade deal.

This contrasts directly with the economic message that “Leave” campaigners pushed in the runup to the Brexit referendum in June 2016. According to the Brexiteers, a UK unshackled from Brussels would give Downing Street more freedom to pursue new commercial ties with a broadly diversified set of partners, including rising China.

But Beijing, like Washington, will see a Britain that looks less unshackled than simply isolated. Britain accounts for just 13.6% of China’s current trade with the EU. Given Beijing’s current trade standoff with the US, and the high likelihood that this is only the beginning of a broader confrontation between the world’s established and rising powers, China will want less political drama, not more, in its global trade negotiations. China has said it’s open to begin detailed negotiations over a trade deal with the UK once the Brexit process is complete, but the uncertainty of Britain’s post-Brexit economic and financial position will continue for many years, leaving China more cautious about long-term commercial commitments with the UK.

Things don’t look much better on the foreign-policy front, another area where “Leave” proponents argued the UK would be better off going it alone. With a current US president who is well-disposed toward Russia and a Europe adopting a policy toward Russian President Vladimir Putin grounded in a pragmatic acceptance of economic realities, particularly on the need for Russia’s energy exports, the UK has chosen a bad time to strike out on its own.

Friendships matter in geopolitics, and while the UK can certainly become a legitimate world power in its own right, it hasn’t had to chart its own foreign policy in decades. It will begin doing so in the most volatile geopolitical environment the world has seen since World War II, leaving little room for error.

Then there’s the future of a post-Brexit European Union. Britain’s bolt from the EU fold won’t immediately threaten the EU. In fact, the hot mess in British politics has certainly helped dampen enthusiasm that some in other EU countries might have for an exit of their own.

But over the longer term, a weaker Europe deprived of one of its most dynamic economies will lose a bit of luster on the international stage. Britain’s departure will certainly empower France and Germany to try to lead more forcefully on deeper European integration, but it’s far from certain that’s a winning proposition for the EU over time, given resistance of various kinds in southern and eastern Europe.

Finally, when it is complete, Brexit will slow the momentum of trade integration that has done so much to create a global middle class and lift hundreds of millions from poverty around the world. In short, this will be the biggest win to date for country-first populism. Brexit will further fragment a global political system that’s already fracturing, and it will generate greater friction in global markets.

Today’s conflicts among the world’s great power are fought over trade and investment. The achievement of Brexit will mark a milestone toward a much more contentious international order.