Alistair Horne describes him as "cherubic, and unflappable, but with a piercing intellect"[2] and "the Foreign Office expect on the Soviets, and Russian behaviour".[2] He was also known to be passionate about equality of opportunity and a less stratified society in Great Britain.[3]
He played an important role alongside US Secretary of StateHenry Kissinger in negotiating the 1973 Agreement on the Prevention of Nuclear War between the United States and the USSR which, according to Kissinger, "owed, in fact, more to British than American expertise".[4] Kissinger described Brimelow's role as "an example of the Anglo-American 'special relationship' at its best, even at a time when the incumbent Prime Minister (Heath) was not among its advocates. There was no other government which we would have dealt with so openly, exchanged ideas so freely, or in effect permitted to participate in our own deliberations."[4]