The phrase "to divide the country" means to create conflict or disagreement among the people in a nation, causing them to have differing opinions, beliefs, or loyalties that can lead to a sense of division or separation. Full definition
The study, which divided the country into six economic regions, reveals that most areas that have the most factories and farms have nitrogen deposition rates higher than the national average. (scientificamerican.com)
It makes me hopeful that this generation will be able talk more openly about the issues that so intensely divide our country today. (nycleadershipacademy.org)
Then, when they aren't in charge, suddenly they are concerned about how divided the country is. (religion.blogs.cnn.com)