This report provides background information and potential issues for Congress on the Navy’s irregular warfare (IW) and counterterrorism (CT) operations. The Navy’s IW and CT activities pose a number of potential oversight issues for Congress, including how much emphasis to place on IW and CT activities in Navy budgets, particularly in a context of constraints on Navy budgets and Navy desires to devote resources to developing “high end” combat capabilities for countering improved conventional military capabilities of countries such as China and Russia. Congress’s decisions regarding Navy IW and CT operations can affect Navy operations and funding requirements, and the implementation of the nation’s overall IW and CT strategies.This report focuses on Navy IW and CT operations. Another CRS report discusses U.S. special operations forces (SOF) across the military services