FROM the outset of the Viet Nam peace talks, the formal meetings at Paris' Hotel Majestic have been counterpointed by private sessions between the U.S. and North Vietnamese delegates. These in turn have apparently influenced Hanoi's conduct of the war. In nearly six months since the talks started, there have been three distinct phases before the present hopeful one:
I: OPENING GAMBITS
May 10: Cyrus Vance and Colonel Ha Van Lau hold "procedural meeting" to work out details for the talks. In Saigon, Viet Cong infiltration of previous ten days tapers off, random sniper and rocket fire ebbs.
May 13: Averell Harriman and Xuan...