The American belief in "free enterprise" has not precluded a major role for government, however. Americans at times have looked to government to break up or regulate companies that appeared to be developing so much power that they could defy market forces. They have relied on government to address matters the private economy overlooks, from education to protecting the environment. And despite their advocacy of market principles, they have used government at times to nurture new industries, and at times even to protect American companies from competition.