Dear Comrade Khrushchev:
Given the analysis of the situation and the reports which have reached us, [I] consider an attack to be almost imminent--within the next 24 to 72 hours. There are two possible variants: the first and most probable one is an air attack against certain objectives with the limited aim of destroying them; the second, and though less probable, still possible, is a full invasion. This would require a large force and is the most repugnant form of aggression, which might restrain them.
You can be sure that we will resist with determination, whatever the case. The Cuban people's morale is extremely high and the people will confront aggression heroically.
I would like to briefly express my own personal opinion.
If the second variant takes place and the imperialists invade Cuba with the aim of occupying it, the dangers of their aggressive policy are so great that after such an invasion the Soviet Union must never allow circumstances in which the imperialists could carry out a nuclear first strike against it.
I tell you this because I believe that the imperialists' aggressiveness makes them extremely dangerous, and that if they manage to carry out an invasion of Cuba--a brutal act in violation of universal and moral law--then that would be the moment to eliminate this danger forever, in an act of the most legitimate self-defense. However harsh and terrible the solution, there would be no other.
This opinion is shaped by observing the development of their aggressive policy. The imperialists, without regard for world opinion and against laws and principles, have blockaded the seas, violated our air-space, and are preparing to invade, while at the same time blocking any possibility of negotiation, even though they understand the gravity of the problem.
You have been, and are, a tireless defender of peace, and I understand that these moments, when the results of your superhuman efforts are so seriously threatened, must be bitter for you. We will maintain our hopes for saving the peace until the last moment, and we are ready to contribute to this in any way we can. But, at the same time, we are serene and ready to confront a situation which we see as very real and imminent.
I convey to you the infinite gratitude and recognition of the Cuban people to the Soviet people, who have been so generous and fraternal, along with our profound gratitude and admiration to you personally. We wish you success with the enormous task and great responsibilities which are in your hands.