A CONTINENT separates the blood-soaked battlefields of Syria from the reefs and shoals that litter the South China Sea. In their different ways, however, both places are witnessing the most significant shift in great-power relations since the collapse of the Soviet Union.

In Syria, for the first time since the cold war, Russia has deployed its forces far from home to quell a revolution and support a client regime. In the waters between Vietnam and the Philippines, America will soon signal that it does not recognise China’s territorial claims over a host of outcrops and reefs by exercising its right to sail within the 12-mile maritime limit that a sovereign state controls.

For the past 25 years America has utterly dominated great-power politics. Increasingly, it lives in a contested world. The new game with Russia and China that is unfolding in Syria and the South China Sea is a taste of the struggle ahead.

Facts on the ground

As ever, that struggle is being fought partly in terms of raw power. Vladimir Putin has intervened in Syria to tamp down jihadism and to bolster his own standing at home. But he also means to show that, unlike America, Russia can be trusted to get things done in the Middle East and win friends by, for example, offering Iraq an alternative to the United States (see article). Lest anyone presume with John McCain, an American senator, that Russia is just “a gas station masquerading as a country”, Mr Putin intends to prove that Russia possesses resolve, as well as crack troops and cruise missiles.

The struggle is also over legitimacy. Mr Putin wants to discredit America’s stewardship of the international order. America argues that popular discontent and the Syrian regime’s abuses of human rights disqualify the president, Bashar al-Assad, from power. Mr Putin wants to play down human rights, which he sees as a licence for the West to interfere in sovereign countries—including, if he ever had to impose a brutal crackdown, in Russia itself.

Power and legitimacy are no less at play in the South China Sea, a thoroughfare for much of the world’s seaborne trade. Many of its islands, reefs and sandbanks are subject to overlapping claims. Yet China insists that its case should prevail, and is imposing its own claim by using landfill and by putting down airstrips and garrisons.

This is partly an assertion of rapidly growing naval might: China is creating islands because it can. Occupying them fits into its strategy of dominating the seas well beyond its coast. Twenty years ago American warships sailed there with impunity; today they find themselves in potentially hostile waters (see article). But a principle is at stake, too. America does not take a view on who owns the islands, but it does insist that China should establish its claims through negotiation or international arbitration. China is asserting that in its region, for the island disputes as in other things, it now sets the rules.

Nobody should wonder that America’s pre-eminence is being contested. After the Soviet collapse the absolute global supremacy of the United States sometimes began to seem normal. In fact, its dominance reached such heights only because Russia was reeling and China was still emerging from the chaos and depredations that had so diminished it in the 20th century. Even today, America remains the only country able to project power right across the globe. (As we have recently argued, its sway over the financial system is still growing.)

There is nevertheless reason to worry. The reassertion of Russian power spells trouble. It has already led to the annexation of Crimea and the invasion of eastern Ukraine—both breaches of the very same international law that Mr Putin says he upholds in Syria (see article). Barack Obama, America’s president, takes comfort from Russia’s weak economy and the emigration of some of its best people. But a declining nuclear-armed former superpower can cause a lot of harm.

Relations between China and America are more important—and even harder to manage. For the sake of peace and prosperity, the two must be able to work together. And yet their dealings are inevitably plagued by rivalry and mistrust. Because every transaction risks becoming a test of which one calls the shots, antagonism is never far below the surface.

American foreign policy has not yet adjusted to this contested world. For the past three presidents, policy has chiefly involved the export of American values—although, to the countries on the receiving end, that sometimes felt like an imposition. The idea was that countries would inevitably gravitate towards democracy, markets and human rights. Optimists thought that even China was heading in that direction.

Still worth it

That notion has suffered, first in Iraq and Afghanistan and now the wider Middle East. Liberation has not brought stability. Democracy has not taken root. Mr Obama has seemed to conclude that America should pull back. In Libya he led from behind; in Syria he has held off. As a result, he has ceded Russia the initiative in the Middle East for the first time since the 1970s.

All those, like this newspaper, who still see democracy and markets as the route to peace and prosperity hope that America will be more willing to lead. Mr Obama’s wish that other countries should share responsibility for the system of international law and human rights will work only if his country sets the agenda and takes the initiative—as it did with Iran’s nuclear programme. The new game will involve tough diplomacy and the occasional judicious application of force.

America still has resources other powers lack. Foremost is its web of alliances, including NATO. Whereas Mr Obama sometimes behaves as if alliances are transactional, they need solid foundations. America’s military power is unmatched, but it is hindered by pork-barrel politics and automatic cuts mandated by Congress. These spring from the biggest brake on American leadership: dysfunctional politics in Washington. That is not just a poor advertisement for democracy; it also stymies America’s interest. In the new game it is something that the United States—and the world—can ill afford.