Re: world peace?
I think a feasable step that could actually be taken toward a more peaceful world would be a strenghtening of international organizations like the UN. Currently the superpowers of the world are part of the UN, but only follow its lead when it benifits them. The US is the perfect example. If such an organization was more powerful then any one or two of its participants it would be able to intervene in squables between nations, and possibly work toward solutions through diplomacy and international intervention. I'm not saying this would immediately produce a world without war, but it should be able to reduce the bloodshed, and, in my mind, it would be a step toward long lasting world peace.
Political activism may get people invested in politics, and affect urgently needed change, but it comes at the expense of tolerance and healthy democratic norms.