Michael Barone mentions,
'In a Univision radio interview during the 2010 election cycle, Barack Obama urged Latinos not "to sit out the election instead of saying, 'We're going to punish our enemies and we're going to reward our friends who stand with us on issues that are important to us.'"
I wish he would take that attitude in foreign policy, particularly in the conduct of the war in Afghanistan. Kill an American and you get a bunch of advisors showing up to build power stations and roads to get you to like us. Welcome the Americans and they ignore you because everything is fine where you are.
Of course, doing this in domestic society where the rule of law is established is the worse sin of a political leader. But in a situation where not the rule of law, but rule itself, the monopoly on violence that is the prerequisite for any government, then punishing your enemies and rewarding your friends is not only forgivable, it is imperative.