For the last decade, the U.S. Department of Defense has spent over five billion dollars on laser weapons that could shoot down guided missiles, unguided rockets, artillery and mortar shells. These efforts have not reached the battlefield. Some systems came close, but the basic problems were that the laser equipment was not rugged enough for battlefield use, and power supplies were not sufficient to fire the laser often enough to be useful.
The billions have not been wasted, but they did buy a lot of disappointment. At the same time, the money and development effort has, slowly, moved the technology towards the point where lasers will be robust enough, and sufficiently supplied with energy, to make themselves effective for the troops. Close now, but not there yet. The Department of Defense fears that a sharp reduction of the defense budget will halt the development money. That would stop work, except for what the manufacturers might continue on their own nickel, and battlefield lasers would remain suspended just short of being useful.
It's not the first time this has happened. At the end of World War II, smart bombs were just coming into use. While primitive, they worked. Same with wire guided missiles ballistic missiles, nuclear weapons and many other bits of military technology we still consider "high tech". Development stopped on most of these systems after the war. Work continued on ballistic missiles and nuclear weapons. Over the next few decades, work resumed on all these, and most are now in service. Thus the end of the development money is never the end of the line.