The massive onshore surges of seawater from tsunamis triggered by the mega-earthquake that struck off northwestern Indonesia on Sunday have caused heavy damage across southern Asia. They are a deadly reminder of how vulnerable humanity is to the destructive forces of nature.

The world's fourth-largest outbreak of tsunamis in a century has left more than 20,000 dead and millions homeless in countries facing the Indian Ocean, including Sri Lanka, Indonesia, India, Malaysia and Thailand. Japan, which is no stranger to tsunami disasters, should provide long-term financial and technical assistance, not just emergency relief. At the same time, the nation should step up its own efforts to prepare for tsunamis spawned by earthquakes that are predicted to occur off the Pacific coast of central and western Japan.

There are always lessons and warnings to be drawn from a natural catastrophe. One flag raised in the latest tragedy is that there is no full-scale tsunami warning system in the Indian Ocean. Another is that coastal towns and villages in the region are almost defenseless against tidal waves in general. In particular, popular resort spots, such as Phuket, Thailand, have no tide embankments along their coastlines.