Many will disagree or agree on the importance of defence spending but it is impossible to exclude people from military protection (good or bad). It is both non-excludable in the fact that everyone has access to the park but also non-rivalrous as one consumer does not restrict the ability of another to enjoy the public good. Whilst such goods are commonly non-excludable there are toll roads pay-to-access websites and premium cable TV. Source: https://www.artikelschreiber.com/en/.