Press reports that President Trump may have revealed sensitive counterterrorism information originating from the Israeli government to Russian officials are potentially disastrous for U.S. counterterrorism efforts. Notably, the Wall Street Journal writes that the information provided by Israel had not even been shared with America’s most important intelligence allies. For the President to disclose this information to Russian Foreign Minister Sergey Lavrov and Russian Ambassador to the United States Sergey Kislyak in what the press reporting indicates was an unguarded moment is a potentially serious breach of U.S. commitments to a vital ally and hurts the overall U.S. reputation for confidentiality. In light of this news, it’s useful to take a step back and run through what foreign liaison relationships do and why they are important to U.S. counterterrorism.

Perhaps more than any other policy instrument, foreign liaison relationships play a vital role in counterterrorism against global terrorist groups like the Islamic State and Al Qaeda. Given the geographic span of these groups’ operations, it is not realistic for the United States to have strong unilateral capabilities in every possible country where they might operate, and even if it were, it would be wasteful. Foreign governments fill this gap, acting as a force multiplier for the United States. Shortly after 9/11, the United States was working with over 100 countries on counterterrorism. In 2005, a senior government official testified that virtually every capture or killing of a suspected terrorist outside Iraq was at least in part due to assistance from foreign intelligence services—a staggering claim.

For their own reasons, liaison services police their own countries against the threats posed by terrorists. Understandably, allied governments see the groups that operate within their borders as a threat to their citizens and their sovereignty. Most jihadist groups operate primarily against the ally and only secondarily against the United States. Indeed, the very problems many local partners have make them necessary for any solution. Governments where Al Qaeda or the Islamic State have a strong presence are often corrupt and undemocratic, creating grievances that terrorists work to exploit. As a result, they become terrorist hotbeds, and thus places where many terrorists can be killed or apprehended. Moreover, because the jihadist network is global, a source might be more easily recruited in a friendly country and then sent to Afghanistan or Pakistan.

In addition to harboring considerable will to go after terrorist groups, allies often have impressive capabilities to do so. Many key counterterrorism allies are autocracies and thus rely heavily on their intelligence services to preserve their power. Even in many developing countries, the intelligence services stand out for their relative competence and power, making them useful partners.

Size is another local advantage. Local services can draw on police and their domestic intelligence services to gather information, as they are often the “front line” of counterterrorism. Their personnel in country dwarfs the size of the contingent of U.S. intelligence officials that might focus on a country. This is true not only in small countries like Jordan, or others like Yemen that are not traditional intelligence targets, but also in key countries of longstanding importance like Egypt. For example, at the end of 2010, the U.S. embassy in Cairo had just under 400 employees; Egypt’s domestic security services, including the police, had between 300,000 and 2 million, depending on which services are included.

Allied intelligence services also have a huge advantage given their knowledge of local languages and cultural awareness. U.S. intelligence is regularly criticized for having too few speakers of Arabic, Punjabi, or other languages that many Al Qaeda and Islamic State members speak. Indeed, the problem for the United States may be even harder, and the role of local services even more important, than is commonly understood. Individuals might speak a particular dialect that even a fluent speaker of the language may not understand. In Pakistan, for example, there are six major languages and over sixty others—and that does not count dialectical variations. Local service members, of course, know their own languages and dialects. Local services are also more likely to know what makes the individual tick and, just as important, how to turn him from terrorist into a source.

As terrorism expert Paul Pillar has argued, all liaison services can take advantage of the law in their efforts to disrupt terrorism and recruit sources. Being a member of a terrorist group or otherwise supporting violence is almost uniformly illegal, and states can simply arrest and question those they believe are linked to either. In addition, they can identify and go after, or at least intimidate, major financiers of terrorism. Local services may use the power of the state to coerce individuals to reveal information. Torture aside, this can range from threats of imprisonment to “encourage” someone who might have a relative in a terrorist organization to pressure on families such as withholding or granting a business permit or the right to attend university, which can lead an individual to reveal information. Going after terrorist logistics is particularly difficult to do without host nation support given the vast nature of logistic activities. For example, Saudi efforts to go after terrorist fundraising, passport production, and recruitment from within the Kingdom played an important role in reducing jihadists’ ability to travel abroad.

These seemingly basic functions are something that the United States cannot do outside its own borders, putting it at a disadvantage in terms of interrogation, gaining pocket litter, stopping support networks, and so on. Moreover, because of these powers, local partners can also take dramatic and far-ranging steps against the adversary, operating on a scale beyond what the United States can accomplish. For example, after terrorism surged in Saudi Arabia in 2003, the Saudi government arrested thousands of suspects.

Liaison services may also have better access to a terrorist stronghold due to geography or historic ties. Sanctuaries are often vital for terrorist movements, and it is often exceedingly difficult for the United States to gain access to them—indeed, if America could, they might not be sanctuaries. It is not surprising that Pakistani intelligence knows Afghanistan, its backyard, quite well. According to press reporting, the United States has worked with Ethiopia’s intelligence service against Al Qaeda in Africa. The Wall Street Journal writes that the United States has “relied on a Saudi intelligence network that stretches deep within Yemen's tribal areas” while the Congressional Research Service adds, “at present, there appears to be significant U.S.-Saudi intelligence cooperation with regard to the AQAP threat.” Indeed, the United States at times even liaises with quasi-states given the importance of liaison—in Somalia, for the example, U.S. intelligence works with Puntland and Somaliland despite the fact that these are not recognized states.

Given these many advantages, it is not surprising that liaison services have had frequent successes in penetrating terrorist movements, often using their own nationals as assets while limiting their support activities. Egypt, Jordan, Morocco, Syria, and Pakistan have all reportedly penetrated terrorist groups. In some cases, certain of these countries will “run” the agent in cooperation with the United States.

The United States also uses foreign governments as jailers, employing them to arrest and detain suspected terrorists who pose potential threats to the United States. The New Yorker reports that Egypt, Morocco, Syria, and Jordan were the primary destinations for rendered suspects after 9/11. This role as jailor serves two purposes. First, and most contentiously, foreign governments interrogate suspects and can share information with the United States. Through its rendition program, the United States has thus been accused of sending over 100 individuals overseas with the express purpose of being tortured. A second, and usually far more important, role of foreign governments is simply to take suspected terrorists off the streets. Individuals might be wanted in Egypt, but there may not be sufficient evidence for them to be tried in the United States. Moreover, because Egypt under Mubarak and other developing world allies often have a low bar for trial and the rule of law, they are able to imprison suspects with relative ease.

Given these advantages, the primary role of U.S. intelligence is to cajole and augment the value of its allies, not replace them. The United States might provide technical assistance, for example, as many U.S. allies, particularly in the developing world, fall far below U.S. capabilities in this regard. Aid in forensics in a post-blast investigation and other specialized expertise represent valuable forms of assistance. In addition, U.S. intelligence often acts as a conductor of global liaison services. For example, the arrest of the Al Qaeda operative and key Jemaah Islamiyya leader “Hambali” involved U.S. coordination of information and action from Indonesia, Malaysia, the Philippines, Singapore, and Thailand. In 2010 Al Qaeda of the Arabian Peninsula attempted to bomb two cargo planes as they neared the United States, using bombs hidden in FedEx and UPS packages. The plot involved not only Yemen and the United States, but also the countries in transit, including Qatar, the United Arab Emirates, Germany, and the United Kingdom. Saudi Arabia provided the key intelligence tip, and Dubai and Britain quickly stopped the flights from going forward and eventually found the bombs. In both these cases the countries in question at times did not cooperate well with each other, but they were able to succeed in doing so because the United States assisted with overall coordination.

Given the importance of these relationships, anything that might jeopardize liaison cooperation could be disastrous. If the United States gains a reputation as a country that cannot keep sensitive information secret or otherwise is not a worthy partner, this could make countries less likely to share information and hinder the fight against terrorism.