Japan's admission to having been driven off Guadalcanal and out of northeastern New Guinea is an indication that her southward progress in the Pacific has reached its limit.
It means that the supply line to Australia and New Zealand from the United States has been freed from the creeping menace which threatened it as the Japanese edged down through the Solomons. It makes even more remote the prospect of a Japanese invasion of Australia.
The marines and the army men who followed them have achieved their objective, which initially was defensive. Now with U.S. forces in full control of Guadalcanal, it should be possible to reverse the Japanese process and sweep northward through the Solomons to flank New Guinea and eventually drive the Japanese out of the entire Melanesian area.
American military and naval men have no illusions about the magnitude of the task. The Japanese are strongly entrenched in the northern Solomons, the islands of the Bismarck archipelago and on New Guinea west of the Buna area, from which they were driven.
They are certain to hang on tenaciously, as they did on Guadalcanal and in Papuan New Guinea. The Tokyo communique speaks of "withdrawal" from both places to operate in other theaters. In the case of Buna, the word "withdrawal" is a euphemism for home consumption.
The Japanese did not withdraw from Buna. They were wiped out. The same is possibly true of Guadalcanal, where there still may be some Japanese stragglers hiding in the jungles and yet to be exterminated. As Secretary of Navy Frank Knox phrased it, the main resistance there has ended. It is possible that they got some forces off under cover of the naval-air engagement recently reported in those waters.
The American and Australian victories, while heartening, are a long way from indicating the beginning of an Allied sweep northward through the Pacific islands towards Japan itself. With the positions they have occupied and the resources they have seized, the Japanese should be able to hold for years unless their navy is destroyed in a great and decisive battle.
Some military observers, in fact, have insisted that Japan will not be beaten by a step-by-step been able to get a debarkation point apparently marks the end of a campaign which began on Aug. 7, at a time when it was feared that the steady southward surge of the Japanese would, unless quickly checked, cut vital American lines of communication with Australia.
The enemy could have used Guadalcanal and the nearby harbor at Tulagi island for direct surface, submarine and air attacks on Australian shipping or could have struck at important American bases, notably those in the New Hebrides and New Caledonia.