Soviet Says Raids Peril 'Coexistence'; SOVIET WARNS U.S. ON 'COEXISTENCE'
Amb Gromyko warns Amb Kohler that Amer policies 'undermine' US-USSR peaceful coexistence, Moscow conf; scores US air raids; reiterates USSR pledge of aid to N Vietnam; Kohler rejects charges; Moscow radio says USSR sees negotiated settlement as only possible solution