This discussion in the British Cabinet took place in 1968. This year was
in some ways the height of the Vietnam War. There were over 500,000 US troops
in Vietnam. In January of that year the Viet Cong launched a major attack
(see Source 4).
There had been a Peace Conference (a sort of permanent committee) for Vietnam
organised by the United Nations in 1954. This continued through the crisis
that began in 1965.
It was jointly run by Britain and the USSR. This was helpful to the USA,
which could put forward ideas through Britain. It was also helpful to North
Vietnam, which could suggest ideas to the conference through the USSR.