There’s a saying among diplomats that now two countries with a McDonald’s have ever gone to war with each other. It’s called the McDonald’s Factor and essentially it means that as soon as a country becomes wealthy enough and integrated into the global economy enough to warrant a McDonald’s, then the cost of war becomes too high.

This idea was crystallized in US Author Thomas Friedman’s book The Lexus and the Olive Tree when he created the “Golden Arches Theory” about capitalist peace. However, shortly after the book was published, NATO bombed Yugoslavia. On the first day of the bombing, McDonald’s restaurants in Belgrade were demolished by the Serbian people and were rebuilt only after the bombing ended. In the 2000 edition of the book, Friedman argued that this exception proved the rule: the war ended quickly, he argued, partly because the Serbian population did not want to lose their place in a global system “symbolised by McDonald’s”.

Critics have pointed to other conflicts as counterexamples, depending on what one considers “a war”:

• The 1989 United States invasion of Panama
• In 1999, India and Pakistan fought a war over Kashmir, known as the Kargil War. Both countries had (and continue to have) McDonald’s restaurants. Although the war was not fought in all possible theatres (such as the Rajasthan and Punjab borders), both countries mobilised their military all along their common borders and both countries made threats involving their nuclear capabilities.
• The 2006 war between Israel and Lebanon, following hostilities ongoing since 1973, with South Lebanon occupied until May 2000. (McDonald’s franchises were established in Israel and Lebanon in 1993 and 1998, respectively.) However, the Lebanese Armed Forces were not a party to the fighting, the Israel Defense Forces action being taken instead against the paramilitary group Hezbollah.
• The 2008 South Ossetia war between Russia and Georgia. Both countries had McDonald’s at the time (restaurants began in the two countries in 1990 and 1999, respectively).
• The 2014 Crimean crisis between Russia and Ukraine. Both countries had McDonald’s at the time.

This chart is fascinating for showing the McDonald’s Factor in action.