BRUSSELS — Western countries increasingly believe the world is heading toward a global war, according to results from The POLITICO Poll that detail mounting public alarm about the risk and cost of a new era of conflict.  Across all five countries polled — the U.S., Canada, the U.K., France and Germany — the vast majority of respondents think the world is becoming more dangerous. The outbreak of World War 3 is seen as more likely than not within the next five years by American, Canadian, French