The Ministry of Defence is set to sign a £3.5bn contract for almost 600 new armoured vehicles.
It comes ahead of a Nato summit in Wales at which Britain will argue for an increase in defence spending from the alliance's 28 member nations.
The order of 589 Scout Specialist Vehicles from a company in south Wales is the largest of its kind for armoured vehicles in over 30 years.
Angus Raffle, 8, says his surprise meeting with the President at Stonehenge was "awesome". His mother says she "squealed like a teenager".
The language has been ramped up at this Nato summit, yet caution appears the order of the day after the mistakes of recent history.
The US President's motorcade pulled up at the school with his black stretch limousine bearing a Welsh flag for the first time in history.