I don't buy that either. There is too much energy dissipated in the atmosphere. Look at all the difficulties they encountered with SDI. They were working with astronomical energy levels. It wasn't because it was a metal target so much as it was that they were LOSING TONS of energy in the atmosphere. At point blank range, sure, but not 5 miles out. The atmosphere is only about 60 miles deep. ICBMs were to be targeted at the very edge of that. Just that little bit of atmosphere, along with diffraction over distance, was enough to weaken their lasers by HUGE amounts.
There's more.
A large percentage of that energy is reflected off the target. Only some of it is absorbed. That fractional part that is absorbed has to melt the metal in a short period of time. Therefore extremely high energy levels are required in order to reliably succeed.
And back to energy.
A 100 watt light on for 24 hours is 8.64 million watt seconds (joules) of energy. Or - 8,640,000 watts for one second. If you laser only works for 10 milliseconds, the peak power level would be 864 million watts. Or the same thing used by a 100 watt light bulb for a day...
High energy lasers don't last long. They generate huge bursts of energy for short periods of time. Therefore in order to do damage to the target in that short period of time the power levels have to be absolutely enormous.