A global war or an intercontinental nuclear exchange is highly unlikely in the current world political climate. But as long as considerable nuclear weapons and long range delivery systems exist in other countries and a developing threat resides with potential adversaries, the possibility of an aerospace attack on North America cannot be discounted. Furthermore, the proliferation of cruise and ballistic missiles, and weapons of mass destruction, has made the post-Cold War world more, rather than less, dangerous. New generations of these weapons may be in the hands of governments or organizations which could threaten the North American continent, or American and Canadian military personnel deployed around the world. Control of North America's airspace is challenged by those who violate the air sovereignty of Canada and the United States. In addition, weapons proliferation coupled with an increasingly unstable world, increases the importance of effective aerospace warning.
             The greatest benefit the Canadian and US governments derive from NORAD is their ability to share the resources and costs needed for aerospace security. It would be militarily impractical, as well as inefficient, for each nation to unilaterally perform NORAD's missions and functions. In Canada's case, although aerospace control would be possible, the mission of air defense in depth would be difficult due to the country's large land mass and relatively small defense force.
             Further, Canada depends entirely on US systems to provide warning of ballistic missile attack, both at home and at overseas locations where deployed Canadian military personnel could be threatened. Although other US military organizations could assume many of NORAD's tasks in aerospace warning, the increased costs and operational difficulties would be compounded by the loss of efficiency that is obtained through cross-border cooperation. In addition, the US benefits from the ability to receive earl...