How does U.S. security assistance affect host nation democratization? This thesis analyzes Department of State and Department of Defense assistance over time to Lebanon and Pakistan to evaluate its effects on the host nation's political rights and civil liberties, measured by Freedom House ratings. In both cases, changes in Freedom House ratings did not correlate consistently with changes in U.S. security assistance. The influence of U.S. security assistance on host nation governance is frequently over-stated. U.S. security assistance has minimal effect on democratization compared to local and regional actors, because it is designed and resourced primarily to accomplish security objectives, not to drive enduring institutional reform. If the United States wanted security assistance to decisively support democratization, then it would need to design and resource security assistance and security cooperation programs differently. Redesigning U.S. security assistance to supersede the influence of other factors on democratization would require increasing funding toward defense institution building, making security assistance conditional on political rights and civil liberties performance, and consistently integrating security assistance within a whole-of-government strategy toward the host nation for a generation or more. Since spreading democracy was a frequently stated characteristic of U.S. foreign policy since the end of the Cold War, it is expected that SA efforts support policy objectives to the maximum extent possible. Funding allocated by U.S. Congress is what enables the executive branch to conduct SA in accordance with applicable laws. If SA supports democratization, then the United States should fund SA liberally if it wants to promote democracy-though it also needs to understand how that mechanism works so it can align funding to the most effective programs. If SA undermines democratization, as some contend,16 then the policy implication is that the United States should reduce SA funding and increase funding for other programs if it wants to support democratization. This would be a dramatic shift; from 1990-2004, overall congressional funding of SA ranged from tenfold to fifty-fold that of United States Agency for International Development (USAID)-administered democracy aid.17 If SA has minimal effect on democratization compared to other factors, then the United States could theoretically pursue its security objectives and democratization agenda somewhat independently. If SA has minimal effect, then the United States also would need to design and resource SA efforts differently in order for them to supersede the influence of other factors on democratization. This research is significant in that it highlights the synergies and tensions between SA and democratization in a way that is policy-relevant. The policy implications of the different answers to this research question are dramatically different and sometimes mutually exclusive. My analysis will cover 1991-2017 for the case of Lebanon; 1990 is when Lebanon's current system of government and military organization were established. It will cover 1980-2017 for the case of Pakistan, because the two waves of U.S. SA were during the Soviet-Afghan war in the 1980s and after the 9/11 attacks.18 Analysis of the different forms of democracy (e.g., parliamentary vs. presidential systems) is outside of the scope of this thesis. The focus is on the functions of democracy as defined above and as measured by Freedom House ratings.