The strategy is a plan to maintain the United States’ military superiority through investments in emerging technology such as autonomy. For example, unmanned aerial vehicles could carry laser weapons, giving operators precision strike capabilities and reducing collateral damage, she said.There are 100mw laser rangers, designators that guide air bombs, missiles, artillery shells and so on. Nevertheless, military officers’ long-held dream of using lasers to destroy targets hasn’t yet been implemented in practice, despite over a decade of development and tests.

The task of heat rejection in such volume in the space context is almost unsolvable; the maintenance of normal temperature is even difficult aboard the International Space Station, even though only astronauts and onboard systems generate heat there. The Navy’s 1000mw Laser weapon is currently onboard the USS Ponce. The system, which has been used operationally in the Persian Gulf, offers military leaders precision accuracy at a low cost, Moran said.Furthermore, one is forced to face insurmountable laws of physics: because of the very low output power 1000mw laser efficiency factor, the enormous amount of heat (a minimum of one hundred megawatts) is generated when shooting from rather powerful guns (more than five megawatts).

First of all, it’s worth mentioning that  have been used by the armed forces of most of countries for a long time. The apparent advantage of laser weapons are their its almost absolute hit precision (if a corresponding pointing system is available) and a maximum beam velocity equal to the speed of light (at the distances under examination, the target is hit almost instantaneously).The laser was part of the US Navy's new Laser Weapon System (LaWS) program, and with a videogame-like controller it had been successfully tested.
http://www.htpow.com/5-in-1-green-100mw … -1006.html
The most popular and widely known 100mw laser MDS project was the Strategic Defense Initiative (SDI, better known as the “star wars” program). The placement of Earth satellites with the weaponry
based on new physical principles, one of which was laser weaponry, was given consideration within SDI. Initially, the project was much too ambitious: it was impossible to put the laser weapons of that time (and even of today) into orbit together with an energy source to recharge it.