Minister for Defence

The title Defence Minister, Minister for Defence, Minister of National Defense, Secretary of Defence, Secretary of State for Defense or some similar variation, is assigned to the person in a cabinet position in charge of a Ministry of Defence, which regulates the armed forces in sovereign states. The role of a defence minister varies considerably from country to country; in some the minister is only in charge of general budget matters and procurement of equipment; while in others the minister is also, in addition, an integral part of the operational military chain of command.

Prior to the 20th century, there were in most countries separate ministerial posts for the land forces (often called "minister for war") and the naval forces. In the interwar period, some countries created a separate ministerial post in charge of the air forces. After the end of World War II, the trend in most countries was to merge the several separate ministerial posts into a single defence minister in charge of all the armed forces. Another common reform which occurred at the end of World War II was to place the defence minister in a national security council, war cabinet, or a "Kitchen Cabinet", which allows the head of government or head of state to coordinate military, diplomatic and economic activities.

The Defence Ministry in some countries is a very important ministry, sometimes considered more important than the foreign ministry. If war is common for a country, the defence minister's position is often assumed by the head of government. (For example, five Prime Ministers of Israel have held the Defense (Security) Ministry during their Premiership). In many nations it is a strong convention that the defence minister be a civilian, in order to highlight civilian control over the military, though it's not uncommon for the defence minister to have some (or even extensive) military experience. In less democratic countries, the minister is often an active military official.

...
Wikipedia