In other cases, the two nations have broken diplomatic relations, but are nevertheless willing to exchange personnel on an informal basis. The protecting power serves as the mechanism for facilitating this exchange. The former embassy of the protected power is staffed by its own diplomatic personnel, but it is formally termed an "interests section" of the protecting power's embassy. Between 1991 and 2015, the Cuban Interests Section was staffed by Cubans and occupied the old Cuban embassy in Washington, D.C., but it was formally a section of the Swiss Embassy to the United States. When relations are exceptionally tense, however, such as during a war, the "interests section" is instead staffed by diplomats from the protecting power. For example, when Iraq and the U.S. broke diplomatic relations due to the Gulf War, Poland became the protecting power for the United States. The United States Interests Section of the Polish Embassy in Iraq was headed by a Polish diplomat.