December always provides an opportunity to pause and reflect on what was and what will be. This year, one of the conclusions that such reflection yields is that the United States remains firmly at the center of the liberal world order. Another is that the U.S. needs to do more to lead in the way that its international standing demands.

Doubts about America’s continued global leadership have been proliferating for years. But, though the much-discussed multi-polar world order may well be in the cards, the reality is that, for now, efforts to address global challenges — from climate change to conflict in the Middle East — demand US. engagement.

Unfortunately, the narrative of American decline has gained so much traction in recent years that even U.S. officials seem to have started to believe it, pursuing weak and piecemeal policies (or, in some cases, doing nothing at all). President Barack Obama’s restrained foreign-policy approach appears to be fueling, not reducing, global instability.

The reasons for this lack of strong action are disputed. Some blame Obama’s own fears about repeating his predecessors’ mistakes; others blame a hostile Congress for tying his hands.

In fact, both factors may be at work. It may well be true that Obama would rather exercise caution — even when bold action is called for — than act impulsively and potentially cause more damage. But the negative impact of an obstructionist, highly partisan U.S. Congress should not be underestimated. For example, by blocking reforms to International Monetary Fund governance that were agreed in 2010, Congress has damaged, perhaps irreparably, the legitimacy and relevance of the Bretton Woods institutions.

Likewise, by refusing to ratify the United Nations Convention on the Law of the Sea, the U.S. Congress has undermined America’s credibility as it attempts to reaffirm international law in the South China Sea, where China is acting with increasing audacity. And, by opposing the inclusion of legally binding climate commitments, it weakened the global climate agreement that was reached this month in Paris, leaving compliance and implementation uncertain.

Stalemate has become the name of the game in U.S. politics in recent years. That is why next year’s presidential election is so crucial. It offers an opportunity for a fresh start, a new approach that produces the type of policy actions that the world needs. The key is engagement — among branches of the U.S. government, between the U.S. government and the public, and between the U.S. and the rest of the world.

For starters, to avoid the kind of obstructionism that prevailed in the last eight years, the next president must engage Congress directly and actively. And, in fact, two of the Obama administration’s recent wins — the passage of so-called trade promotion authority (fast-track negotiating authority to conclude the Trans-Pacific Partnership) and the reauthorization of the small but vital Export-Import Bank — were the result of dedicated outreach, education and, yes, cajoling of lawmakers.

The Iran nuclear agreement, one of Obama’s hallmark achievements, involved similar efforts to engage Congress, from protracted trips to Capitol Hill by Obama administration officials to a creative approach that allowed legislators to display their displeasure for the deal, without blocking its progress. Even in America’s highly divisive political atmosphere, it seems, where there is a will, there is a way.

America’s next president must also improve engagement with citizens, whose widespread disaffection constrains — or allows — U.S. leaders to pursue a weak foreign policy. Like many Europeans today, most Americans do not seem to understand — or care to understand — that the crumbling of the liberal world order would have dire consequences for all of them.

It was not always this way. Immediately after World War II, the memory of war, together with the enduring threat posed by the Soviet Union, made plain the importance of building and maintaining a liberal world order. Today, though the need for such an order is just as great, the argument is not nearly as comprehensible or emotionally powerful. Discussion of rules and institutions comes across as bloodless. It is up to political leaders — and especially the president — to figure out how to make a compelling case about what is at stake.

Only this approach can secure the mandate from the public that the next U.S. president will need to engage effectively with other world leaders. And make no mistake: Such engagement is indispensable. While the U.S. must play an integral role in addressing global challenges, from ending the Syrian civil war to following through on the promises of the Paris climate agreement, it cannot do it alone. Real progress will demand real cooperation.

In the second half of the 20th century, the U.S. showed that committed leadership could help to ensure widespread stability and prosperity. In the 21st century, it has showed how devastating a lack of such leadership can be. Finger pointing will not fix anything. Only by pursuing genuine, deep and sustained engagement, both at home and abroad, can the next administration ensure that the coming years will be better than the last.

By Ana Palacio

Ana Palacio, a former Spanish foreign minister and former senior vice president of the World Bank, is a member of the Spanish Council of State and a visiting lecturer at Georgetown University. — Ed.

(Project Syndicate)