CHICAGO-A volcano erupts in Iceland, and the effects ripple around the globe: A mom in Romania frets about making her son's wedding in Texas. A florist in New York worries shipments won't arrive. Patients awaiting treatment in Nigeria have to wait another week for the doctors.The fallout from the ash cloud looming over Europe illustrates just how interconnected our world has become.Thousands of planes fly millions of passengers and tons of cargo each day, providing the economic lifeblood of nations and businesses. The flights deliver products for sale or items as small as a specialized tool that lets a factory keep operating.The planes also bring medicines to hospitals and food aid to earthquake or hurricane victims. And they bring war and peace. Soldiers are often transported to and from hot spots by air.Tales of woe and inconvenience span every social level, from the Norwegian prime minister who got stuck in New York and had to govern using his iPad, to ordinary people who saved money for trips of a lifetime, then had to abandon those plans.