The recent Icelandic volcano eruptions, and the thick clouds of gritty ash they have put over the North Atlantic and northern Europe, halted most commercial flights in the areas covered by ash for a while. But the U.S. Air Force has kept troops and cargo moving to Afghanistan and Iraq. This has increased costs, because the longer southern route, via Spain and Dubai, must be used. Very sick or badly wounded troops being flown to American military hospitals in Germany, are instead being sent, via the southern route, directly to the United States. This does not endanger the patients, because the medical flights carry medical personnel and equipment to handle any possible medical emergencies. Only patients who are stabilized are sent on these flights.
One group of troops are harmed by the ash clouds, those that are taking the two weeks leave provided for troops are in Iraq or Afghanistan for a year. These troops depend on commercial flights for travel to and from military bases in Dubai and Germany. About a thousand of them are stranded, along with civilian passengers, on both sides of the Atlantic. Others have to delay their leave until the ash situation subsides, or more European countries admit that they overreacted to the ash threat.