Re: To Infini
"I always wondered if there was some sort of non-competition agreement between the UK and US after WW2."
One way of looking at it is that the USA won the Second World War, and everyone else lost. Even countries like Britain who "won", were left with massive debts, half ruined industry from bombing, and memorials where half the male population should have been.
The US wound up being owed money or reparations by most of the planet, whilst having take basically no damage to it's territory, and the massive war industry could be quickly repurposed into providing luxury goods like cars.
Old empires like Britain, France or Japan were no longer competition, and war-time spending had pushed US industry and technology to new heights. (Where countries like the UK had helped to develop the atom bomb, they could now be told to jog-on with impunity).
Unsurprisingly, for the next fifty or so years, the US basically ruled the world.