So let's say you're a nation, and you feel it is your responsibility to police the World for whatever reason. You've got to be careful of a few things. There are lots of different ideologies out there, and although they are not always consistent with yours, they've probably been around for thousands of years. So even if these ideologies are barbaric (by your assessment), they are probably entrenched within those societies, so be careful.
Do you have the numbers? No? Can you get them? No? Then you run the risk of spreading yourself to thin. Probably not a good idea, especially when things aren't going particularly well at home. The numbers don't lie, so do the math before venturing out to spread the love. The love may not always be welcome. At least not in the way you think it should be.
Is it okay to help out with humanitarian aid? Sure! By all means! But know where to draw the line. There's only so much you can do.
Never neglect your own house. That's the most important thing. Take care of things on the home front because if your residents ever think you're ignoring internal infrastructure at home, they probably won't support your efforts elsewhere.
Go slowly, make as many friends as you can, build relationships, and try to stay out of conflicts, which don't involve you. There may be some drastic exceptions, but for the most part, you should be able to figure out what they are ... hopefully.
What if it's too late? You've already spread the love, and you've already spread yourself too thin. There are too many fires throughout the world, and you're involved everywhere. Support for your involvement is faltering, both internationally and domestically. What's next? Well, you've got a couple of choices:
First choice: You can stay the course and try to outlast those, who are giving you problems. But remember; the numbers are not on your side. Sooner or later you'll run out of resources and it's game over. Busted and bankrupt, both morally and financially. You'll have become little more than a microscopic blip on the geopolitical time line. Sorry! Try again.
Second choice: Slowly but methodically, pull back. Plain and simple. Well perhaps not so simple, but plain. Let everyone know that you're having a hard time sustaining an international presence, and it's getting to be time to do some major renovations on the home front. Step back and let the chips fall where they may. It might become extremely painful for a while, but that's the best hope for your survival.
So if you're an empire on the verge of a nervous breakdown, step back for a moment, and go into rehab for a while. Maybe do some work around your own house for a bit. Rebuild the foundation, and reevaluate your priorities.
Good luck, have fun, and play safely.