because of the following cbs news special report, "the merv griffin show" will begin one half hour later than usual. >> the president of the united states tonight disclosed a vietnam peace offer that he says has been secretly offered to the communists. the plan calls for withdrawal of all u.s. forces within six months and new south vietnamese elections in exchange for a cease-fire and return of all american prisoners. >> the offer that i shall now present on behalf of the government of the united states and the government of south vietnam, with the full knowledge and approval of president thieu, is both generous and far-reaching. >> the response from north vietnam was, no, you're missing something. you've got to overthrow the government. but we were not going to overthrow an ally as we left. that was the sticking point. >> we were stuck. it was a stalemate. >> this is the scene on the white house lawn as the presidential helicopter waits for president nixon to begin what must be surely one of the