The Israeli government does not disclose information on the overall size of the IDF, or the identity, location, and strength of units. In 1988, the International Institute for Strategic Studies in London estimated the strength of the ground forces at 104,000 troops, including 16,000 career soldiers and 88,000 conscripts. An additional 494,000 men and women were regularly trained reserves who could be mobilized within seventy-two hours. According to The Military Balance, in 1997-1998 there were 175,000 soldiers in the regular Israeli army (conscripts and career soldiers) and 430,000 in the reserves. These reserve forces consisted of 365,000 in land forces, 10,000 in the navy and 55,000 in the air force. As of 1999 Jane's estimated the
active duty strength at 136,000 troops. In 2004, the International Institute for Strategic Studies estimated the strength of the ground forces at 125,000 troops, including 40,000 career soldiers and 85,000 conscripts, with an additional 600,000 men and women in the reserves.