a really wonderful book

Curious. In my first industrial job my boss was

" In October 1939 Butement turned to this technology as a potential solution. He conceived of a highly compact RDF set placed on the projectile, setting off the detonation when close proximity to the target was attained. He completed the circuit design, but there was the problem of packaging such a device in a small projectile, as well as the question of the vacuum tubes surviving the acceleration forces at firing."

The design got shipped off America in 1940 by the Tizard Mission "and subsequently a variation of his circuit became adopted in the United States as the proximity fuse or VT (variable-time) fuse, the most-manufactured electronic device of the war".

"As well as the dramatic breaking of Japanese Naval air power in the Battle of the Philippine Sea, it immortalised the invention's impact with the battle's alternate name: The Great Marianas Turkey Shoot, where the battle losses were so severe that it led to the Japanese adoption of the kamikaze".

Neither microwave radar nor the proximity fuse were US inventions.

My first year supervisor for Physics was one of the three inventors who figured out how to make a regenerative feedback Doppler trigger fuse. When he died his Times obituary read "Edward Shire - a device to destroy the flying bomb". Manufacture of them and magnetrons were outsourced to the USA (he worked on both and had stories of working behind a hot radar in a corotating shed - heating his lunch in the microwave beam).

UK gave away a lot of very important high technology secret military technology to be manufactured in the USA out of reach of German bombers.

Making a cheap small thermionic valve that could withstand the 20000g acceleration of an artillery projectile was critical to its success.

Yeah, we used to be friends and allies.

A gruesome film (still worth watching if one can stomach it) about the

1979 Sino-Vietnam war called "The Youth":

No glory there, only guts. The Chinese film makers are remarkably honest about how vicious the Vietnamese were with respect to anyone else setting foot on their land, even their former "allies."

Yuk. I'll stick to romantic comedies.