Currently you can stream Act of Valor with a Netflix subscription in the United States. If you have a Netflix subscription already then you won't have to pay anything extra to stream this movie.
If you don't have a Netflix subscription then you can still buy or rent Act of Valor to watch online from a few digital platforms including Redbox, FandangoNOW, Google Play Movies, VUDU and Microsoft Store. It'll cost you as little as $1.99 to rent the movie and $7.99 to buy the documentary.