Firangpolicypundit Fareed Zakaria notes that the American strategy of playing off Shia vs. Sunni in Iraq resembles that of British India (via Amardeep Singh):

The intractable security problems in Sunni areas coupled with some success in Shia ones might lead the Iraqi government (and Washington) toward a “Shia strategy” in Iraq… In many of its colonies the British would often favor a single group as a quick means of gaining stability. Almost always the results were ruinous—a trail of civil war and bloodshed.