missile defense capabilities to protect the United States, as well as our friends and allies. These initialcapabilities emerge from our research and development program and build on the test bed that we have been constructing. While modest, these capabilities will add to America's security and serve as a starting point for improved and expanded capabilities later, as further progress is made in researching and developing missile defense technologies and in light of changes in the threat.
September 11, 2001 underscored that our Nation faces unprecedented threats, in a world that has changed greatly since the Cold War. To better protect our country against the threats of today and tomorrow, my Administration has developed a new national security strategy, and new supporting strategies for making our homeland more secure and for combating weapons of mass destruction. Throughout my Administration, I have made clear that the United States will take every necessary measure to protect our citizens against what is perhaps the gravest danger of all: the catastrophic harm that may result from hostile states or terrorist groups armed with weapons of mass destruction and the means to deliver them.
Missile defenses have an important role to play in this effort. The United States has moved beyond the doctrine of Cold War deterrence reflected in the 1972 ABM Treaty. At the same time we have established a positive relationship with Russia that includes partnership in counterterrorism and in other key areas of mutual concern. We have adopted a new concept of deterrence that recognizes that missile defenses will add to our ability to deter those who may contemplate attacking us with missiles. Our withdrawal from the ABM Treaty has made it possible to develop and test the full range of missile defense technologies, and to deploy defenses capable of protecting our territory and our cities.
I have directed the Secretary of Defense to proceed with fielding an initial set of missile defense capabilities. We plan to begin operating these initial capabilities in 2004 and 2005, and they will include ground-based interceptors, sea-based interceptors, additional Patriot (PAC-3) units, and sensors based on land, at sea, and in space.
Because the threats of the 21st century also endanger our friends and allies around the world, it is essential that we work together to defend against them. The Defense Department will develop and deploy missile defenses capable of protecting not only the United States and our deployed forces, but also our friends and allies. The United States will also structure our missile defense program in a manner that encourages industrial participation by other nations. Demonstrating the important role played by our friends and allies, as part of our initial missile defense capabilities, the United States will seek agreement from the United Kingdom and Denmark to upgrade early-warning radars on their territory.
The new strategic challenges of the 21st century require us to think differently, but they also require us to act. The deployment of missile defenses is an essential element of our broader efforts to transform our defense and deterrence policies and capabilities to meet the new threats we face. Defending the American people against these new threats is my highest priority as Commander-in-Chief, and the highest priority of my Administration.