In a speech of extraordinary gravity, President Kennedy told the nation Monday night that the United States was imposing a naval and air quarantine on Soviet military shipments to Cuba. This is a frightening and dangerous decision, but anyone concerned for the safety of this country and the peace of the entire world should recognize that it was a decision that had to be made.

The President has received intelligence reports and aerial photographs which document the existence of an offensive missile capacity in Cuba. In view of Kennedy's go-slow attitude in the past and the gravity of his words Monday night, neither his appraisal of the military danger nor the resulting commitment of the United States to action can reasonably be disputed.

As the President made clear, the situation in Cuba now goes beyond the question of United States-Cuba relations. The American blockade is not directed against Castro, because Castro poses no military threat to our security. It is directed against the Soviet Union, and it is the Soviet Union which must have bear the responsibility for any breach of the peace which may occur.

To demand that the Cuban government purge itself of Soviet military presence within 48 hours or face American military action would have been both naive and dangerous. On September 13, President Kennedy assured the American people that the United States was ready to move against Cuba if and when the evidence indicated that "an offensive threat does exist." He stressed that the presence of an offensive missle capacity or the development of a Soviet military base would constitute such a threat.

It is naive to hope that after encouraging Communist bloc aid, both military and economic, for over two years, and after ignoring specific United States warnings about military activity, the Castro government will suddenly accept an American ultimatum to get rid of the Russians.

Had the Cubans been frightened by the prospect of United States action, they would have turned from their reckless course a month ago in the face of Kennedy's declared intention to prevent the establishment of a Soviet base. But the sad truth is the Castro government is no longer a free agent and any appeal to it at this time would not only be self-delusion, but might also be interpreted as a sign of weakness.

Whether Castro is a Soviet puppet or not is no longer the issue. It would certainly be dangerous to delay action in the Caribbean in the hope of proving once and for all that Cuba is subservient to Moscow, if that delay might give the Russians the impression that we don't really mean what we say. Offering "rapprochement" in the form of a diplomatic ultimatum would not only seem hypocritical to both Cuba and the Soviet Union, but could also involve them in a serious miscalculation of American willingness to honor stated commitments.

The United States is and should be committed to the elimination of Soviet military power in Cuba, because the presence of medium and intermediate range missles constitutes a direct military threat to the United States and its allies in the Western Hemisphere; because that presence is in violation of the pledge given repeatedly by the Soviet government that Russian aid to Cuba has been purely defensive. And finally, because Soviet missile bases in Cuba undermine the status quo in the Cold War geographical balance of power which has kept the Western Hemisphere off limits to Soviet military penetration.

Despite the charges of political opportunism and deception that have been levelled against the President, his decision was not an easy one to make. It would have been far safer to have delayed, in the vague hope of obtaining United Nations support for our position, or in the assumption that our opponents are reasonable and decent men. Decisive action was the best way to win the support of our neighbors in the Western Hemisphere, as yesterday's overwhelming vote of confidence by the Organization of American States demonstrated.