There’s been a lot of talk lately about the defence budget, and how many planes and ships the UK can afford.To try and shed some more light on the subject, The Telegraph sent its Defence and Security correspondent, Dominic Nicholls, on a mission: to build his very own Telegraph Air Force.So where does one go to do their Air Force shopping?The Royal International Air Show, of course. The US defence secretary told his British counterpart that Washington is “concerned” that the UK’s military power and diplomatic influence is “at risk of erosion”.General Mattis said he wanted the UK to remain America’s “partner of choice” but also said that the French were committed to being “global actors” alongside the US.Mr Williamson has been pushing for extra cash, stepping up his efforts after the NHS was promised a funding boost. Dominic Nicholls tests out some kit This was compounded by a leaked letter from Pentagon chief Jim Mattis to Mr Williamson, which hinted that the special relationship could be under strain unless the UK boosted its defence capability. A row continues to rage in Whitehall between Defence Secretary Gavin Williamson and the Prime Minister over defence funding.Mrs May has refused to commit publicly to Britain remaining a “tier one” military power, raising fears in the Ministry of Defence that Britain’s military status could be in jeopardy. Which is why The Telegraph’s defence expert travelled to the Royal International Air Tattoo to learn just how much it costs to build an air force.Watch the video to find out if Dominic managed to stick to budget, even with a discount. Britain’s Prime Minister Theresa May (R), her husband Philip May (C) and Britain’s Defence Secretary Gavin Williamson attend the national Armed Forces Day celebrations Credit:OLI SCARFF/AFP Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.