Training programs without broader reform will fail. Starting small will be essential. The United States will need to thoroughly vet small-unit leaders as well as senior officers. Improving governance is also vital. This is not usually a question of financial aid or broader democratization but rather of ensuring that corruption is kept to a minimum and basic services are provided.

At the same time, as the United States tries to rectify past failures, it must also exploit the Obama administration’s genuine successes. In the case of the Islamic State, the United States must also be prepared for the full collapse of the so-called caliphate, which has steadily seen its territory, recruitment of foreign fighters and funding dry up. Should it continue to lose ground, many of its local fighters will go underground, and some among the tens of thousands of foreigners will return to their homes or go to other countries, spreading terrorism. The group itself will encourage lone wolves as a way to show its own supporters, as well as its enemies, that it remains strong. In other words, victory will not be complete when Raqqa falls.

In other places, the best U.S. hope may be to contain the violence. Syria’s neighbors, for example, host millions of refugees, and several, such as Jordan, Lebanon and Turkey, already face a considerable threat from terrorism. Aiding these countries’ counterterrorism services, assisting with border security and helping them bear the refugee burden all will make the terrorism problem less likely to spread and increase overall stability.

The United States cannot and should not be everywhere. Part of President-elect Trump’s job will be drawing lines between areas of strong and peripheral interests. Some might be better left to allies: France, for example, could continue to take the lead in parts of North and West Africa. Just as the American public should not empower amateurish or failed terrorist plots by overreacting, the next administration should direct its considerable, but still finite, power at actual threats.

IT MAY prove harder for the new president to navigate domestic waters than the shoals of the Middle East. Since 9/11, three of the biggest failures in U.S. counterterrorism policy have involved domestic politics.

The first is institutionalization. Under Presidents Bush and Obama, new and controversial counterterrorism instruments—targeted killings, increased domestic surveillance, aggressive FBI sting operations, detention without trial and so on—are at the heart of counterterrorism. In addition, the United States is bombing the Islamic State in Iraq and especially in Syria with only dubious legal justification.

Since 9/11, counterterrorism policy has been decided by the executive branch and modified by the courts. One branch of government, perhaps the most important in the long term, has been AWOL under both Democratic and Republican leadership: the U.S. Congress. Regardless of whether you want to expand or shrink the above policies, public debate and legislation are vital. This puts the executive branch and the courts on a sounder footing and enables longer-term planning necessary for programs to develop properly. It also ensures that government lawyers do not have to tie themselves in knots or unnecessarily limit operations because the legal niceties are missing.

Yet this weak domestic base for counterterrorism reflects a second failure: resilience. Terrorism deaths at home since 9/11 have proven low, but fears of terrorism remain high. In a landmark speech in 2013 and in subsequent remarks, President Obama has tried to talk down the threat, describing Al Qaeda as on “the path to defeat” and noting that another 9/11 is unlikely. He failed. Alarm over Islamic State atrocities, even though it did not directly involve the U.S. homeland (or even many American citizens), led to a spike in fear of terrorism. It remains easy for a terrorist group to sow fear and disrupt America: even small attacks like the Boston Marathon bombings paralyzed a major city. The new president will have to walk a fine line to assure the American people that he takes the threat seriously without stoking fears that play into the hands of terrorists.

Finally, this election risked jeopardizing one of America’s greatest counterterrorism successes: integration of immigrant communities. Muslims’ trust in the government and security services is low in many European countries. Add such a sense of humiliation to a surging Far Right political movement that constantly blasts Muslim immigrants and citizens, and the conditions for radicalization are strong. In contrast to Europe, the American Muslim community is far better integrated and regularly cooperates with law enforcement.

Unfortunately, Trump’s demonization of the American Muslim community will endure beyond the election even if he walks it back. This card is on the table, and other politicians are likely to pick it up. Ideally, the new president should press state and local officials to work with Muslim communities, not just to stop radicalism in their ranks but to protect them from right-wing extremists. Good relations, and a recognition that Muslims face daily security threats, will help ensure that radicalization remains low and that, when it occurs, the community cooperates with law enforcement.

Donald Trump has a lot on his hands. He must understand the changing nature of terrorism, revise U.S. policy in the Middle East, and address the domestic concerns of resilience and rising Muslim discrimination. While the primary counterterrorism challenge may well be the civil wars that fuel the worst groups today, and which certainly defy easy solutions, the incoming administration will inherit a tremendous counterterrorism apparatus. In spite of failures, inefficiencies and hard lessons, it has accomplished its primary objective for the last fifteen years: averting another 9/11. A stronger and improved counterterrorism policy can continue to keep the threat limited and, over time, diminish it further.

Daniel Byman is a professor and the senior associate dean at Georgetown University’s School of Foreign Service and a senior fellow in the Center for Middle East Policy at Brookings. His latest book is Al Qaeda, the Islamic State and the Global Jihadist Movement: What Everyone Needs to Know. Follow him @dbyman.

Image: A U.S. Marine engages a target with an AT-4 light anti-armor weapon. Flickr/U.S. Marines