It is with the greatest respect and sympathy that I write, hoping that this letter might help the great people of Japan find a way to rebuild part of their shattered country in a positive way.
While it is impossible for any country to construct a defense wall around its entire coast, it is feasible to construct large mounds or dikes that could at least slow a tsunami and thus give much needed time for people to escape. Might I suggest that the Japanese people embark on a tsunami defense program, using the one resource that they — much like every other industrialized nation — have in abundance: waste/garbage?
It would be feasible to divert household waste away from designated landfills and transport it to coastline sites, where large earth-moving vehicles would slowly compress thousands of tons of the material with soil thrown up on the shoreline by dredging barges — until mounds as high as 20 meters and as wide as 50 meters were constructed. These mounds could then be covered over and landscaped. This process could continue along the coastline to the extent that the people and the government felt was necessary.