No. We do not have the resources and we do not really have the capability of knowing the things the "world's policeman" should know.
The US simply does not have enough money to go off and solve all the world's problems. We have a huge deficit and interventions cost a lot of money.
Furthermore, we are not gods who always know how and when to intervene. There are many disputes in the world that are too complicated for us to understand and to judge properly. Also, many of these disputes are not really helped by having outside powers try to solve them.
The world is too big and too complicated for us to act as its policeman. Doing so will bankrupt us and make us hated as we make what various people see as mistakes when we try to solve others' problems.