After many years, the Council on Foreign Relations (CFR) once again listed the Balkans as a stability problem. CFR is considered by some to be the most influential foreign-policy think tank in the United States. Its impressive membership list has included senior politicians, more than a dozen Secretaries of State, CIA directors, bankers, lawyers, professors, and prominent media figures. CFR is perhaps best known by the general public as the publisher of the widely read bi-monthly journal Foreign Affairs. In policy circles, CFR is known for its "David Rockefeller Studies Program," which often succeeds in influencing foreign policy by making official recommendations to the President and diplomatic community, testifying before Congress, speaking with the media, and publishing on issues of foreign policy.
The CFR's annual Preventive Priorities Survey (PPS) for 2018 evaluated ongoing and potential conflicts based on their likelihood of occurring in the coming year and their impact on US interests. This report warned specifically of "escalating tensions or extremist violence in the Balkans - Albania, Bosnia and Herzegovina, Croatia, Kosovo, Macedonia, Montenegro, and Serbia, resulting in political instability and armed clashes", and rated the likelihood moderate but the impact on US interests low. This "tier III" rating has nevertheless excited a good deal of interest, even though it is no more than a recognition in Washington of what people in the Balkans have known for years – economic recession and social decay are taking a toll.
According to the CFR report, the risk of renewed violence and political instability is growing in the Balkans. The decade of progress in post-conflict reconciliation and economic recovery after the US-led interventions of the 1990s has stalled and has now, in some areas, even gone into reverse. The international agreements that brought peace to the region, based on the principle that preexisting borders should not be moved to accommodate ethnic differences, are fraying and could unravel with unwelcome consequences for the United States. A repeat of the prolonged and intense military conflicts that blighted the Balkans in the 1990s is unlikely according to the CFR, however, violent instability are a real possibility. This scenario could cause extensive ethnic cleansing, crimes against humanity, challenges to existing state institutions, border changes, further radicalization, and a new refugee crisis for their European allies.
The CFR states that predicting the sequence of events that could cause this instability is impossible, not least because incidents in one country would reverberate in neighboring areas, but nevertheless several flash points or triggering incidents include potential secessionist attempts in Bosnia and Herzegovina, Kosovo and Macedonia, terrorist attacks or political assassinations, and alleged Russian destabilization. Ethnic politics in the Balkans are interconnected. If Republika Srpska tries to leave Bosnia and Herzegovina, it could trigger an attempt at secession by Croat communities along Croatia's border, some Serbs in northern Kosovo will try to leave Kosovo, and some Albanians in southern Serbia will try to leave Serbia. Some Muslims in Serbia could also want to unite with what remains of Bosnia and Herzegovina. If Macedonia is partitioned, its Albanians could want a union with Kosovo and potentially with Albania and Albanian-majority municipalities of southern Serbia, which would trigger the ethnic partitions of Bosnia and Herzegovina, Kosovo, and Serbia.
Among secessionist movements, as the most serious problem listed is an independence referendum in Republika Srpska, an entity within Bosnia and Herzegovina that has had a Serb majority since the ethnic cleansings of the 1990s. Its president, Milorad Dodik, has repeatedly promised that Srpska will vote on independence. Still, international recognition would be limited, as even Serbia would not want to ruin relations with the US and EU. Such referendum could precipitate a Bosniak Muslim military move to seize the northeastern town of Brčko that links the two "wings" of Republika Srpska and is vital to its survival, and Serbia would then have to decide whether and how to intervene as it did in the 1990s. Without any doubt, secessionist attempt by Bosnian Serbs would also provoke a similar attempt by Bosnian Croats, embroiling a NATO ally in conflict.
The similar troubling factors are Serbian-Albanian relations in Kosovo, and Albanian-Macedonian relations in Macedonia. Albanian rioting against Serbs in Kosovo, as occurred in March 2004, could precipitate Serbian military action to protect the Serb-majority municipalities in the north, perhaps even with NATO concurrence. Serb nationalist provocations, such as blocking Albanians from access to Serb-majority areas or ostentatious displays of nationalist symbols, could trigger an Albanian effort to seize the north by force, because even now the area is only loosely controlled by Priština. In Macedonia, Albanian paramilitaries like those that rebelled in 2001 and again in April 2015 could seek union with Kosovo or Albania, forcing the Macedonian government to choose between repressing the rebellion or allowing Macedonian paramilitary forces to respond.
The less probable scenario is a terrorist attack or political assassination. An attack by the self-proclaimed Islamic State or al-Qaeda targeting Christians in Bosnia and Herzegovina, Macedonia, Montenegro, or Serbia could trigger revenge attacks against Muslims and even cross-border fighting that could spread to other countries. Assassination of political leaders could precipitate intervention by a neighboring state. The CFR also claims there's potential Russian destabilization of Bosnia and Herzegovina, Montenegro or Macedonia. Allegedly, Moscow can back Milorad Dodik in Republika Srpska, ethnic Serbs concentrated in northern Montenegro, and Macedonian nationalists associated with former Prime Minister Nikola Gruevski. However, most of such claims are only a part of the Russophobia campaign propagated before the ratification of the Montenegro's agreement with NATO.