For hundreds of foreign companies in the lucrative but perilous pursuit of business in violence-racked Iraq, security – especially the use of private forces instead of military personnel – has become an increasingly vexing issue. As violence surged to new levels last month, many companies felt a need for the help of more security personnel. But they – as well as the US government, which hires private contractors for some security roles – are finding it harder to persuade highly trained, professional guards from the private sector to put their lives at risk, observers say.The result, critics fear, may be a growing force of less disciplined, more mercenary guards thrown into a volatile situation with few rules to guide their actions. Within Congress and among security experts, concern about the proliferation of private-sector guards in Iraq is mounting. Full Story