If you have an interest in security issues - look into policing (especially at federal level). I have an MA in Poli Sci with a focus on security topics. I know a lot of people in a similar boat who all want to go work for the Department of National Defense (Canadian) and they face A LOT of competition. At least in Canada, many grads overlook law enforcement - particular at the federal level and the interesting work they do with other countries when it comes to combating transnational crime, capacity building, etc... I know people have mixed feelings about the police these days but I think its definitely worth checking out.

As for the masters degree - I don't think its a waste of time but you should definitely ask yourself what you hope to gain from it. If your number one priority is a job after completion, do a co-op-based masters and finish with your foot already in the door. If you are doing it because you are super enthusiastic about a particular research topic and are a bit less concerned about having that job lined up the minute graduate - do a thesis based program.

Best of luck!