Both Hillary Clinton and Donald Trump have made clear, to varying degrees, that they're suspicious of big free trade agreements. Trump has gone further and questioned some of America's most durable and valuable relationships with other nations. While some of this can be dismissed as campaign rhetoric, the consequences of such talk are far-reaching. At a time of major economic and political realignments in the world, the United States is in danger of alienating allies and fomenting uncertainty in its relationships with major trading partners.
Once, this might not have mattered, as no other nation could rival the U.S. as the world's economic and political hegemon. But times have changed. If the U.S. voluntarily withdraws from the world, one country — China — is better positioned than any other to fill the void.
China no doubt recognizes the opportunity presented by growing protectionist sentiment in the U.S. Even before Trump's rise injected an isolationist streak into the campaign, the Chinese government had grown more disciplined and savvy in its approach to international engagement.