We Brits (and the French) hype US interest in us, as market, partners, or competitors (See Wiki on Belfast's market, see any TSR.2 "conspiracy" post: both "sacrificed" under "US pressure". None of the above: frankly, my dears, they didn't give a darn). US Aero, Mid-70s, was all about MDC/Lockheed avoiding Convair's civil fate under market change: potential deregulation of US domestic air transport (actioned from 1977 by new Pres.Carter). What products would a new carrier-industry seek? GD gave up design, happy to build great chunks of DC-10/747, bill and run; MDC sought to turn DC-10 into a Big-Twin; France wanted to make an aeroplane out of Mercure (led not by Aerospatiale/Airbus, but by Dassault). BA, trading from April,1974, wanted its fleet to come from Seattle. HSAL had stayed in Airbus as a private venture when UK Govt. pulled out in April,1969, but few A300B2 had been sold. A310 in 1976 was looking for funding: AI's owners told HSAL to stump up, or lose the wings, even of A300B4 too. UKGovt. had decided to nationalise HSAL+BAC (who had a trickle of 1-11s and little else), as BAe. (trading 29 April,1977). Italy had chunks of DC-9/10.
In early 1977 MDC and Boeing saw Euro-Aero as bankers: it was our money they wanted, cos they had our market locked up (see UTA/DLH/AZ DC-10). UK PM Jim Callaghan despaired of making any sense of the airframe industry he was about to own: he already owned RR who lobbied against any airframe money, which would be instead of Govt spend on RB211s into US types. So did GEC, who owned 50% of BAC and looked forward to unloading it without further investment. He went off to Washington for a weekend with MDC and Boeing, who offered him participation in their projects. His Memoirs talk of them treating him as from a less-developed country. The Boeing offer of BAe. 757 wing was to Boeing-design, at Boeing-imposed price. He came back, invested in A310 Launch Aid to secure the wing (and soon bought back 20% equity in AI), funded various RB211s, and gave BA freedom to act commercially - so to reject 146 for 737-200(ADV), to launch 757 as bespoke Shuttle People-carrier, and to take 767-200 (on which he imposed, ludicrously, heavy RB211-524H for routes where its advantage - cruise efficiency, would never be realised). France told Dassault to stick to Mirages; Italy took chunks of MD80/MD11 and suffered much pain...though less than MDC.