That's almost certainly true, and it may be less than 40 years. Northrop-Grumman has already produced a 100kW solid-state laser capable of being mounted on a fi

That's almost certainly true, and it may be less than 40 years. Northrop-Grumman has already produced a 100kW solid-state laser capable of being mounted on a fighter or a small ship (http://articles.latimes.com/2009/mar/19/business/fi-laser19 http://articles.latimes.com/2009/mar/19/business/fi-laser19), and apparently they think that vehicles mounting it are ten years or less away. Serviceable, ruggedized laser rifles are probably 10-20 years down the road from that -- and will mean an enormous increase in infantry ammunition capacity and firepower, probably on the order of magnitude of the introduction of the automatic rifle. (Manufacturers of rechargeable batteries suddenly sound like a very good investment.) US infantry tactics as they currently exist will not be well-suited to wars involving such weapons; a retired Marine gunnery sergeant, H. John Poole, has written a number of books on the need for the US to develop autonomous light infantry, and has pointed to the prospect of laser weapons as one of the reasons for this need.