War is a reality check for all the weapons and equipment troops have. For example, in the last decade, U.S. forces have found that they have some serious communications problems. This is kind of old news, but the cell phone generation expects to have the same comms on the battlefield that they had back home. While dropped calls on your cell phone is annoying, the same thing happening in combat can get you killed.
Lots of stuff interferes with radio signals. As cell phone users know, it's hard to get a signal in many buildings or underground (subways, road or train tunnels). Same deal in combat with longer range FM or AM radios. In addition to the cell phone type hassles, troops have to worry about sand storms (which does all sorts of bad stuff to call quality) and nearby electric lines.
As troops become more dependent on their individual radios (widely introduced in the last decade) these interference problems become more of an issue. One solution is a high energy mode for transmitting (more wattage), but there are technical and potential interference problems. In short, as convenient as individual radios are, dropped calls are a constant threat.
The personal radio problems are just the tip of the iceberg. There are a lot more battlefield devices using radio. These include operator controlled aircraft and ground vehicles, as well as sensors. While these devices have been designed to deal with jamming (robots go on automatic and either stay in the same area, or come "home"), lost signals are another one of those unpredictable events that can ruin your day.