Missile defense could also be a system, weapon, or technology involved within the detection, tracking, interception, and destruction of attacking missiles. Missile defense are often splitted into categories supported various characteristics: like type/range of missile intercepted, the trajectory phase where the intercept occurs, and whether intercepted inside or outside the Earth's atmosphere. The role of defense against nuclear missiles has been a heated military and political topic for several decades. However, missile defense is not any longer limited to interception of strategic nuclear weapons. The gradual development and proliferation of missile technology has blurred the road between the technologies for the interception of tactical missiles and therefore the interception of strategic missiles. Journals contain articles that peer reviewed, in an effort to make sure that articles meet the journal's standards of quality, and scientific validity. Each such journal article becomes a neighborhood of the permanent scientific record.