San Francisco International Airport (SFO) FAA Status: Advisory Due to RWY-TAXI / CONSTRUCTION, there is a Traffic Management Program in effect for traffic arriving San Francisco International Airport, San Francisco, CA (SFO). This is causing some arriving flights to be delayed an average of 47 minutes.
I'm fairly sure that I could get over a thousand wars in Europe in the last Millennia or so. So I'd say that there have probably been between 10,000 and 250,000 wars in human history. I'd expect a log distribution with very few wars with more than 100 million participants and a great many with fewer than a thousand.
World War I (also known as the First World War, The Great War or the War to End all Wars) involved more than twenty sovereign nations over several fronts for more than four years of heavy fighting, with both sides employing tactics and technology that made the war unlike any before it.