The American people are concerned. Worries surround the Visa Waiver Program, the refugee and migrant crisis in Europe, and the ever increasing number of domestic terror plots. A recent Gallup poll lists terrorism as the number-one concern of Americans.

While most Americans want to see more homeland security protections, it is critical they understand that security at home actually starts overseas; what happens there has a major effect on the potential for terrorism here.

The American Enterprise Institute (AEI) and the Institute for the Study of War (ISW) have co-authored a report that emphasizes the connection between foreign action (or inaction) and domestic security, rightly noting that “[d]efensive and internal measures will not adequately protect Americans at home.”

The report analyzes Islamist terrorist groups and finds that al-Qaeda and, to a lesser extent, its affiliates have focused on the West as the prime target for their aggression. The Islamic State (ISIS) has been more focused on defeating local leaders and governments and controlling territory. However, as the report argues, both are ultimately after the same two goals to overthrow and replace Muslim governments and to destroy and subjugate the Western world.

And so, what the U.S. does about al-Qaeda, ISIS, and other violent Islamist groups abroad directly affects U.S. homeland security. There is a human tendency to break down issues to understand them better. This is all well and good, but in focusing on the different parts of an issue, one cannot lose sight of the larger whole. In this case, the U.S. cannot discuss homeland security issues without also considering the larger diplomatic, strategic, military, and intelligence realities.

If you are concerned about the potential threat posed by refugees, then you should also be concerned about the ability of our intelligence community to vet them and thus the resources and capabilities of the community to do so. You should also care about the broader U.S. strategy toward the chaos in Iraq and Syria that is creating so many refugees, about whether our policies are helping or hurting our security at home.

If you are worried about the growing number of terror plots at home, then you should also be worried about how well the U.S. is working with its foreign allies to shut down the terrorist safe havens that allow them to plan, organize, and train for terror attacks. You should also care about the U.S.’s ability to dedicate enough military resources to protect our security interests, which include helping to maintain political and economic stability in key regions.

The president is charged with the responsibility of wisely and effectively utilizing diplomatic, military, and intelligence resources to secure and defend America’s interests. But he or she cannot do so without proper resources, thus Congress also has a critical role to play in protecting our country, and it falls short in this task when it fails to challenge bad policies that harm U.S. interests or to support those that help. At present, the tools available to the president are too few and in poor condition and are increasingly inadequate to protecting security and prosperity at home.

At a time when the U.S. is focusing on domestic counter-terrorism efforts, we must also be thinking strategically about the foreign threats it faces, given their potential to impact the homeland.

Foreign engagement, providing our intelligence community with the resources and tools it needs, and investing in a military that is prepared and capable to defend our country are sometimes unpopular, but they are essential to a holistic homeland security strategy that is both relevant and effective in today’s challenging world.