Israel Defense Forces | 119,885 followers on LinkedIn. The Israel Defense Forces (IDF) is the military of the State of Israel, responsible for the nation's defense and security. Founded in 1948, the IDF ranks among the most battle-tested armed forces in the world, having had to defend the country in six major wars. At the age of 18, men and women are required to do mandatory military service in one of the IDF's three branches - Ground Forces, Air Force, and Navy.