What weapon from the Korean War does Wolcheck reintroduce to the French military in the novel, The Ugly American?

American military observer, Tex Wolcheck, advises the French to use a weapon that worked well in Korea. It is a truck that carried twenty 5-inch rocket launchers mounted in a circle. The launchers fire simultaneously, killing everyone within a hundred yards. American ingenuity is handed over to the French and they use it to great effect. Despite the success in using it, Wolcheck and Major Monet receive strong criticism from the generals and admirals because the weapon strays from traditional military tactics. The weapon is extremely effective, but like the great advice from Monet and Wolcheck, it will not be used again because it breaks Western military traditions and conventions.