Propaganda is a message. Soft power is a means.
For example, Voice of America publishes "Learning English" radio/tv broadcasts, podcasts, and news articles. They are produced with a limited vocabulary (I think a few thousand words), shorter sentences, and are spoken slower. They often match up with native language reporting of current events so you can listen to both for context clues.
Having people all over the world able to speak a basic level of English helps further the dominant role of the US in international trade, allows our military to use friendly locals as translators anywhere they go, and gives people around the world some level of "connection" with us - shared common ground to work from.
VoA does not broadcast propaganda, they hold themselves to a very high standard of reporting only the truth. Which is why repressive governments hate it, as do people who want to create them.
Is your claim that Va primarily produces English language learning material and the content is secondary?
>VoA does not broadcast propaganda, they hold themselves to a very high standard of reporting only the truth.
Seriously?
Do you have any specific counter examples?
FWIW I am not American.
Their Wikipedia page in the controversy section lists at least 5 specific examples where they were criticized for direct political messaging - so certainly not a neutral party (whatever that means).
Also you seem to think propaganda means “not true” when it more often is true things that promote your interests. What matters is someone is paying to highlight information over other perspectives.