The U.S. Navy Military Sealift Command Henry J. Kaiser-class fleet replenishment oiler USNS Tippecanoe (T-AO 199), left, refuels the Royal Canadian Navy Halifax-class frigate HMCS Winnipeg (FFH 338) during an underway replenishment prior to participating in Keen Sword. Keen Sword is a joint, bilateral, biennial field-training exercise involving U.S. military and Japan Self-Defense Force personnel, designed to increase combat readiness and interoperability of the Japan-U.S. alliance.