The Israel Defense Forces differs from most armed forces in the world in many ways. Differences include the conscription of women and its structure, which emphasizes close relations between the army, navy and air force. Since its founding, the IDF has been specifically designed to match Israel's unique security situation. The IDF is one of Israeli society's most prominent institutions, influencing the country's economy, culture and political scene. Following 1967, the Israel Army has had close military relations with the United States Army, including development and cooperation, such as on the F-15 jet, and the Arrow missile defense system.