We are strengthening each of the three legs of our strategic forces. The cruise missile production which will begin next year will modernize our strategic air deterrent. B-52 capabilities will also be improved. These steps will maintain and enhance the B-52 fleet by improving its ability to deliver weapons against increasingly heavily defended targets. We are also modernizing our strategic submarine force. Four more POSEIDON submarines backfitted with new, 4,000 mile TRIDENT I missiles began deployments in 1980. Nine TRIDENT submarines have been authorized through 1981, and we propose one more each year. The new M-X missile program to enhance our land-based intercontinental ballistic missile force continues to make progress. Technical refinements in the basing design over the last year will result in operational benefits, lower costs, and reduced environmental impact. The M-X program continues to be an essential ingredient in our strategic posture, providing survivability, endurance, secure command and control and the capability to threaten targets the Soviets hold dear. Our new systems will enable U.S. strategic forces to maintain equivalence in the face of the mounting Soviet challenge. We would however need an even greater investment in strategic systems to meet the likely Soviet buildup without SALT. STRATEGIC DOCTRINE This Administration's systematic contributions to the necessary evolution of strategic doctrine began in 1977 when I commissioned a comprehensive net assessment. From that base a number of thorough investigations of specific topics continued. I should emphasize that the need for an evolutionary doctrine is driven not by any change in our basic objective, which remains peace and freedom for all mankind. Rather, the need for change is driven by the inexorable buildup of Soviet military power and the increasing propensity of Soviet leaders to use this power in coercion and outright aggression to impose their will on others. I have codified our evolving strategic doctrine in a number of interrelated and mutually supporting Presidential Directives. Their overarching theme is to provide a doctrinal basis, and the specific program to implement it, that tells the world that no potential adversary of the United States could ever conclude that the fruits of his aggression would be significant or worth the enormous costs of our retaliation. The Presidential Directives include: PD-18: An overview of our strategic objectives PD-37: Basic space policy PD-41: Civil Defense PD-53: Survivability and endurance for telecommunications PD-57: Mobilization planning PD-58: Continuity of Government PD-59: Countervailing Strategy for General War.