Insurgents capturing cities across Northern Mali had the government there requesting French assistance, while failing policing in many parts of Libya has the government there asking for NATO help. The forms of assistance these countries have requested extend well beyond training missions. Both have invited intervention into their security sectors to rectify governance problems that have resulted in an inability to enforce the rule of law in crucial areas of the state.

As the United States and its allies withdraw from the major conflicts of the past decade, we are likely to intervene going forward only with the cooperation of host states. During his recent West Point commencement address, President Obama called for this type of international mission to be at the forefront of our security policy and announced his intention to use new funding to “train, build capacity and facilitate partner countries on the front lines,” including in Libya and Mali. French troops are already in Mali, and NATO recently declared itself ready to assist in response to Libyan authorities’ request for support to “develop their security sector.” But can such invited interventions succeed?

Invited interventions are proliferating as a response to weak states. Weak states pose a risk to international security through the spread of conflict and other transnational threats, but institutional reform — the solution proposed by the World Development Report in 2011 — requires mechanisms to lock leaders in as the changes become more costly, and to build confidence among civilians to participate in governance. Even with incentives to improve governance, leaders in these states may find it impossible to make these commitments credibly and back them with sufficient capacity. When domestic invitation brings a foreign intervention, these missions seek to improve governance in fragile or failing states by replacing indigenous personnel with foreign personnel. In many such cases, which I term in my research “governance delegation agreements,” missions extend beyond training and advising: International personnel actually participate in governance, although they do not fully take over the government. They aim to create an especially capable or “untouchable” force to carry out the tasks for which they were invited to intervene. These may include anything from tracking and arresting armed thugs to revamping a judicial system. They are, however, only invited when the political incentives of host states and international actors align, and their authority is limited to roles specified in the resulting agreement.

Invited interventions may be useful, but we should be cautious in what we expect them to achieve. Research I conducted recently in regions close to engaged external powers, Melanesia and Central America, shows that requested interventions can achieve some success in the short term. But the findings also remind us that this kind of assistance can only succeed at tasks the host state is willing to cede authority on — complex tasks like developing a security sector or defeating an insurgency require greater authority. In the long term, we know little about what effect these missions will have, as most are recent.

Noteworthy cases, such as the Regional Assistance Mission to the Solomon Islands (RAMSI) in 2003 and the Strongim Gavman Program (SGP) to Papua New Guinea (PNG) in 2005, introduced Australia-led Pacific Island Forums missions to improve governance and strengthen the rule of law. Results varied depending on the degree of authority delegated to the mission. RAMSI was tasked with combating militias that formed after the Asian financial crisis, continually drained the treasury through extortion, and denied the government capacity to enforce the rules. More than 2,000 foreign troops, police and other personnel were assigned authority above Solomon Islands personnel, as well as specific exemptions from local prosecution, although their presence required annual review and contained a termination option contingent upon a majority vote. RAMSI succeeded in restoring the rule of law and strengthening governance, leading to a dramatic drop in crime and improvements in other indicators, such as infant and child mortality.

Most host states, however, place greater constraints on invited external actors’ authority because existing governance capacity is somewhat stronger than in the Solomon Islands. Less authority leads to more limited success. After RAMSI, a proposal for a similar project in PNG followed. PNG faced limits on policing and controlling resources, but it was a fragile rather than failed state. Some elements of the ruling coalition resisted allocating Australia much authority, holding out especially on provisions to exempt foreign personnel from local prosecution. The two actors settled on the SGP in which Australian officials received only “in-line” positions where foreign personnel made decisions together with PNG officials. SGP had both independence and capacity, but it had considerably less authority than RAMSI. Subsequently, the agreement has succeeded only in accomplishing less complex tasks: certain government offices received more resources to provide services, and there are some indications that crime may have dropped slightly, but the major improvements seen in the Solomon Islands did not occur in PNG.

Beyond Melanesia, missions have often been scaled back and have accomplished only in simpler, short-term tasks. The International Commission against Impunity in Guatemala (CICIG) was tasked with reestablishing the rule of law there. After Guatemala’s civil war ended in 1996, it was no longer considered a failed state, but crime remained high: In particular, impunity was so bad that a U.N. representative in 1997 called it “a good place to commit a murder, because you will almost certainly get away with it.” The U.N. commission, invited by the government, can investigate criminal charges, and, if invited, share authority as a co-prosecutor. It can also recommend institutional reforms and removal of corrupt individuals. Like SGP, CICIG succeeded in simpler tasks like securing convictions. Although CICIG deliberately selects especially difficult cases, available data suggest its involvement as a co-prosecutor results in a conviction rate above 60 percent, compared with less than 10 percent otherwise, during the period analyzed. But while crime may have dropped slightly, there is currently no indication of success in more complex tasks, such as substantially reforming the state’s institutions. The longer term implications of these invited interventions are not yet known.

These cases suggest that the interventions recently invited in Africa may succeed in tasks such as locating criminals, helping prosecute specific states and perhaps even driving rebels out of regions. They rarely succeed, however, in complex tasks that require greater coordination, such as reestablishing the rule of law or developing the institutions necessary to provide consistent security. These arrangements temporarily substitute indigenous personnel with foreign personnel, but their authority is limited by the scope of the invitation from the host state. The level of fragility or failure influences whether the host state can retain more authority, thus more limits are likely in less failed states. Such limits make coordination more difficult. If we choose to participate in invited interventions in states like Libya, we must recognize that this paradigm limits us to simpler tasks and, perhaps, a focus on short-term fixes.

Aila M. Matanock is an assistant professor of political science at the University of California, Berkeley. Her research on this topic is part of a larger project of which a piece is forthcoming as an article in Governance entitledGovernance Delegation Agreements: Shared Sovereignty as a Substitute for Limited Statehood.”