What does it take for the government to warn against travel to a particular country? Japan has an overheated nuclear reactor from which dangerous levels of radioactive material have been released, a record earthquake with powerful aftershocks and the possibility of more to come, as well as a devastating tsunami. But our 'severe threat' black alert is in effect only for Fukushima, the area that has been directly affected, and three other prefectures. In the same category is the entire Philippines, where a gunman killed tourists half a year ago, and Egypt, where protests last month toppled a dictator. It is not entirely clear what the government means by its categorisation of these countries, but it is clear what it is not doing - helping prevent risk to life and limb.

Japan has been put in the second category of red alert, 'significant threat', which means avoiding non-essential travel. It has got Bahrain, Lebanon and Tunisia, nations experiencing political uncertainty, for company. Risk assessment is not a precise science, but it uses knowledge, understanding and common sense as a basis. Whatever the Security Bureau is using to come up with these various determinations, it does not seem to be working.

The world has little experience of nuclear reactors gone awry and only a limited grasp of earthquake prediction. What is known, though, is that all of Japan lies on a fault line and aftershocks, big and small, are certain along any part after a major quake. The highest alert should have been issued as soon as word of last Friday's disaster was known. That it was not has put lives at risk. Unless there is a black alert, refunds on tours and travel are not mandatory. Financial concerns are as a result being put ahead of safety as people go ahead with plans. Raising the alert to black days after the quake does not restore confidence in the system. The keeping in place of the alert against the Philippines eroded faith; it is there not because of a pervasive threat, but it seems more because of dissatisfaction with the Philippine government's handling of the shooting. Until it is reflective of true circumstances, it is of limited worth.