The existence of these efforts doesn't say much about their effectiveness, which is marginal at best. Notice how the 'successes' are always in perfect conditions. Decades of Soviet propaganda did next to nothing, yet suddenly, Russian propaganda is the most effective thing imaginable. Or a US-government-sponsored letter writing campaign by the better-off Italian Americans to their Italian relatives is credited with helping influence an election in struggling post-war Italy. There's a huge selection bias for the times there's even a hint of any kind of effect.