Opinion on American military intervention

1.How do you view the American military when it comes to being a "world police" and do you think they should be
2.Do you think that the American military is guilty of using disproportionate force on civilians in modern day wars and past wars. Ex: Afghanistan, Iraq, Vietnam
3.At what point do you think the American government should use military intervention with other sovereign countries
4.Do you think the American government using 'covert action' is ever acceptable. As in secret missions the public doesn't know about American influence in other countries Ex: propaganda campaigns, coups de tats, regime change