The U.S. Navy is building Virginia class submarines, and recently completed the conversion of four Ohio class submarines from Trident Ballistic Missile Submarines (SSBN's) to Guided Missile Submarines (SSGN's). The Virginia class is the first nuclear powered fast attack submarine (SSN) that shipyards designed with SOF capability without requiring conversion. The SSGN conversion of the first four Ohio class submarines included substantial SOF capability. These construction and conversion projects represent a significant investment in SOF and amphibious capabilities, and they follow a long line of submarine conversions that began early in World War II. By analyzing three World War II operations, this monograph argues that knowing what actually happened in amphibious operations conducted and supported by American submarines in World War II provides valuable insight about the scope of capabilities, challenges and benefits of submarines for these kinds of missions in naval warfare. The first operation is an amphibious raid on Makin Atoll. The second involves the amphibious landings on the northwest Africa coast as part of Operation Torch. The final operation includes the landings on Attu Island in the Aleutian chain.