Clausewitz defines war as an “act of force to force our enemy to do our will”. The nature of war is long-lasting, but its character changes over time. Current U.S. strategic leadership is advancing the view that since the character of warfare has changed to focus on irregular warfare, then the U.S. military should prepare for a future of irregular warfare. This shift in focus forgets that the nature of war is long-lasting and that, to be successful, we must prepare for all types of conflict. This document will define the types of conflict and the likelihood of each, followed by a discussion of U.S. strategic guidance, and ending with an analysis of the training resources and force structure requirements necessary to achieve success in all types of conflict. Regular or conventional warfare is defined as war “typically between uniformed, state-sponsored armies with high casualties, a high tempo, and a high consumption of resources.” Irregular warfare is a broad term that encompasses many different aspects of conflict against mostly irregular forces. Some of the aspects of irregular warfare include security force assistance, counterinsurgency, unconventional warfare, foreign internal defense, peacekeeping, stability operations, and counterterrorism. Hybrid threats combine aspects of conventional and irregular forms of warfare. Regular, irregular, and hybrid threats all describe the different characteristics of warfare that exist in the enduring nature of warfare. Historically, the United States has frequently been involved in irregular warfare since its conception. Robert Scaife's article in the Small Wars Journal discusses the few instances in which the U.S. military engaged in regular warfare stating that, "During the 20th century, the United States probably engaged in... middle of the paper... . warfare capabilities in the process. The U.S. military can succeed in future wars if it focuses, trains, and adapts its force structure to prepare for more likely challenges to U.S. national security interests international terrorist organizations, transnational criminal organizations, rebellions, and small wars. The most dangerous challenges to US national security interests come from major conventional threats such as Russia, Iran, North Korea, and China dangerous, the United States must focus its strategic guidance on full-spectrum operations, increase training in conventional operations while maintaining current training in irregular operations, and improve force structure with irregular operations facilitators while maintaining its power conventional. capacity.