Bill Clinton and Al Gore, who in their two terms in office established one of the most successful White House relationships to date, show how even a good relationship between a president and a vice president can come under tremendous strain. Clinton had broken with tradition by choosing as his running mate a fellow Baby Boomer from the same part of the country, rather than balancing the ticket geographically. But in the end, no matter how close the two figures are personally, it’s never forgotten who is the president and who is the deputy. Clinton and Gore rarely argued over policy (the Clinton adviser George Stephanopoulos was Gore’s verbal-sparring partner, generally believing that the vice president was a bit too dreamy).

But soon enough Clinton and Gore differed over whether to bomb Serbia, where Muslims and Serbs were engaged in a brutal war over hegemony in the area. Clinton, inexperienced in foreign policy, had campaigned on being more muscular in world affairs than his predecessor, George H. W. Bush, which sometimes led him to issue threats he would later regret. After a strong and lengthy argument within the administration, Clinton announced a somewhat vague but robust policy toward Serbia and dispatched Secretary of State Warren Christopher to line up European support. While Christopher struggled to sell America’s allies on the new approach, Clinton got cold feet, having read a Wall Street Journal op-ed by Arthur Schlesinger Jr. arguing that the new policy would spread violence in the area. Gore typed up a point-by-point rebuttal. He also advocated bombing, which Clinton resisted.

Clinton’s Serbia plan, such as it was, was abandoned for the nonce. When Serbian ethnic cleansing of Muslims became intolerable, the United States entered the Balkan wars, which ended in the defeat of Serbia, and peace through the Dayton Accords in 1995. (Also, Clinton and Gore had a serious falling-out over Clinton’s reckless affair with Monica Lewinsky in the study right off the Oval Office—from which their friendship never recovered. Presumably, though, this won’t be a frequent problem.)