Writing for the New York Times in 2009,[4] Montgomery called upon the West to stop thinking that it could "establish fully functioning multiethnic societies in Bosnia and Kosovo with no change in borders".

[5] In 2011, the Serbian newspaper Blic revealed that Montgomery had been engaged as a consultant to SNS leader Tomislav Nikolic "to help him improve his party’s image in the USA and the EU, but also help him win power in Serbia" for some 7.500 euro a month.

[6] In 2016, Montgomery published his memoirs book "When the applause dies down - Memories of the last American ambassador to Yugoslavia", in which he contests the consensus among the U.S. foreign policy elites on the need to keep Bosnia and Herzegovina together and to support the independence of Kosovo.

[8] In late December 2024, while guest on Serbian TV, Montgomery criticized the adoption of the United Nations General Assembly Resolution 78/282 and minimised the Srebrenica genocide, claiming that “genocide” is a “stretched qualification”, using instead the terminology of “terrible crime” as in the Serbian narrative on the July 1995 massacre.

In the same interview, Montgomery claimed that the Dayton Peace Accords should have established three entities instead of two - a long-term goal of Bosnian Croat nationalist parties.

[9] At the end of his tour as Deputy Chief of Mission, the Bulgarian government awarded him the Order Of The Madara Horseman, First Class.