World . By FRED WEIR MOSCOW — Last week the USSR mark- ed the 72nd anniversary of the October Revolution with the traditional military parade in Red Square and all the usual fanfare. Beneath the flowing red banners and the martial salutes, however, there was no concealing the doubt and uncertainty that pervaded the occasion this year. The USSR is facing its most difficult Revolution Day celebration since that des- perate, icy cold morning in 1941 when the troops marched grimly past the Lenin Mausoleum and continued marching straight out to Moscow’s outskirts to the trenches against the attacking Nazis. Then, at least, the enemy and the threat were clear. Today there is widespread fatal- ism and near psychological collapse — particularly among the Soviet intelligentsia — which seems almost as intense as if they had actually lost a war. What makes this so perplexing to a sympathetic outsider is that there has been no defeat, only an over- whelmingly healthy process aimed at dis- mantling an outworn, burdensome political bureaucracy and sweeping away an oppres- sive web of historical mythology. What is happening in the Soviet Union today can only be likened to a revolution. An entire power structure, social system and economic mechanism have reached their limits of growth and are in deep crisis. Everywhere one looks today, the shell of the past is cracking open and new energies — not always constructive ones — are forcing their way out. It is trite but apropos to note, a la Mao, that a revolution is no tea party: it is a turbulent, bewildering, _ psychologically bruising and profoundly disorienting event for the vast majority of people. At this time of year Soviets are supposed