29 SEPTEMBER 1961, Page 4

On August 13 Herr Ulbricht, under Soviet orders, began to

seal off the one remaining escape route from East to West. It was an event likely to rank with Sarajevo, as one of the decisive moments of history. Yet surprisingly little attention has been paid to why it happened—or why it happened when it did.

Constantine FitzGibbon has been in- vestigating the subject; and he will present his conclusions about AUGUST THE THIRTEENTH In next week's 'Spectator.'