The paper’s second part examines the legacy of the Obama administration in the field of international security assistance. It provides a brief overview of the most remarkable new global, regional and country programs initiated by the United States between 2009 and 2016 as part of the prolonged War on Terror, mainly, in South Asia, Middle East and North Africa, as well as in response to a shift in strategic balance of power in the Eastern Europe and the Asia-Pacific. The paper also studies various effectiveness and impact assessments of relevant programs and also the projects of reforming the whole system of security cooperation elaborated by both expert community and politicians. The conclusion is drawn that the reform approved by the Congress in the early 2016, after Donald Trump’s victory in the presidential election, constitutes a compromise which consolidates a new distribution of roles between the Department of Defense and the State Department and increases transparency and accountability of the programs funded and administered by the DoD. The current reform is aimed at increasing the level of effectiveness (quite often very low, as Obama’s rule has shown) of the U.S. efforts in building capacity of the foreign military forces, border control and police units in countering domestic and transnational security threats. However, the positive effect of this reform – especially in the most fragile states affected by violent conflict – and the success in mitigating numerous and various risks related to provision of foreign security assistance – is not given.