After a period of comparative quiescence, following their repulse in the Coral Sea action, the Japanese resumed activity in the Indian Ocean and Pacific at the end of May.
Their most important move was made against Sydney, headquarters of the Allied naval forces in the South-West Pacific. Here, at least four submarines of "special" type managed to enter the harbour on the night of May 31, but accomplished nothing beyond torpedoing an ex-ferry vessel used as a naval depot ship. All four submarines were destroyed by gunfire or depth charges. One of them has already been salved from the shoal water in which she sank, and is reported to be somewhat bigger than the midget type used in the attack on Pearl Harbour on December 7, 1941. The latter were stated by the U.S. Navy Department to be 41 feet in length, but according to messages from Sydney, the vessel recovered there is at least 60 and possibly nearly 75 feet long.
It would appear, therefore, that the Japanese, finding the tiny craft used in their Hawaiian attack to be a failure, have now built somewhat bigger vessels in the hope of overcoming the defects of the original design. To judge from the fate of the four submarines at Sydney, this hope does not seem to have been realized.
In all probability these small submarines were launched from a depot ship of some description, which must have approached within 100 miles of the Australian coast to give her brood a chance of success. Naturally every effort will have been made to run down and sink this parent vessel, but she is probably a fairly fast ship and has therefore been able to make her escape. Australian and Dutch aircraft engaged in hunting for her were fortunate enough to locate four enemy submarines at sea, off the New South Wales and Queensland coasts. There of these are considered to have been destroyed beyond doubt, having been bombed as they were about to submerge. They were larger vessels than those which entered Sydney Harbour, and were evidently cruising independently against commerce. One of them had torpedoed a ship just before she was intercepted. A bomb which hit the submarine amidships caused her to break in two and sink, with the loss of all but five of her complement of 42. It is possible that she was Ro. 33 or Ro. 34, submarines of 700 tones, launched in 1933-34, and armed with four torpedo tubes and a 3-inch gun.
At Diego Suarez, the naval base in the north above Madagascar occupied by British forces as a precautionary measure, a Japanese submarine attack was defeated on May 30. In order that the enemy might gain no useful guidance for the future, the Admiralty refrained from publishing details of this affair, beyond stating that no casualties were sustained in any of H.M. ships. A claim made in Tokyo to have damaged a battleship of the Queen Elizabeth type and a cruiser of the Arethusa class on this occasion, has been definitely denied. Probably it was made in the hope of eliciting some sort of information.
On June 3 an air raid was delivered on Dutch Harbour, the U.S. naval station in the island of Unalaska, on the southwestern edge of the Bering Sea. As headquarters of the U.S. Navy in Alaskan waters, this harbour is of some importance, though it is by no means a first-class naval base. Nor is it well adapted as a starting point for attack upon Japan, 2,000 miles distant, weather conditions in the intervening seas being bad for most of the year. Four bombers and 15 fighters carried out this raid, which lasted 15 minutes. High-explosive and incendiary bombs were used, but no damage of note was done. Two further visits from enemy aircraft followed, but no more bombs were dropped. It seems fairly certain that the planes came from an aircraft-carrier. In this way the Japanese may have hope to excite popular apprehensions on the Pacific coasts of the United States and Canada to such an extent as to divert forces which could be more usefully employed elsewhere.
A much more serious affair was the attack on Midway Island, an American naval air station, 1,125 miles to the N.W. of Hawaii. According to official communiques issued by Admiral Chester W. Nimitz, Commander-in-Chief of the U.S. Pacific Fleet, the attack was opened on June 4 by a strong force of bombers from enemy aircraft-carriers. After American fighter aircraft had repulsed these with heavy loss, Japanese naval forces approached the island. Up to the time of writing, these had been decisively defeated with the loss of two if not three aircraft-carriers, with all their planes. This is of the first importance, since it is upon the possession of an adequate force of aircraft-carriers in the Pacific largely depends. One or two more aircraft-carriers have been more or less badly damaged, as have three battleships, four cruisers, and three naval auxiliaries or transports.
This is the heaviest blow that has so far been inflicted on the Japanese at sea, and may well prove to be a turning-point of the war. That it should have occurred over possession of a minor position such as Midway may seem strange; but probably the enemy considered it a thorn in their side, from which U.S. reconnaissance aircraft could keep watch over their dispositions in the Marshall Islands and neighbouring groups, 1,000 miles and more to the south-westward.
If the enemy idea was to catch the defenders of Midway napping, after an interval of nearly three months since the island was last attacked, they certainly miscalculated badly.
In the Atlantic, U-boat attacks on shipping off the American Atlantic coasts continue to cause serious concern. On June 5 it was announced in New York that the Royal Navy was assisting U.S. naval forces with corvettes and trawlers to combat this menace, in view of the limited experience which our Allies have had in anti-submarine warfare. So long as the enemy are able to sink merchant vessels faster than they can be replaced, the war is by no means won.
Another phase of the German war against shipping can be seen in the constant air attacks upon convoys proceeding to North Russia. Owing to the proximity of enemy air bases in Norway and Finland, the Germans are invariably able to attack in force, which our defending fighters, fewer in number and often obliged to descend into the sea when their fuel is exhausted, are faced with an unequal contest. Though the recent German claim to have destroyed 18 ships in a single convoy has been described by the Admiralty as exaggerated by 175 per cent, these losses cannot be regarded with equanimity.
In the Mediterranean the Italian fleet shows no sign of enterprise. On the few occasions on which it has ventured to sea it has been so severely mauled that it now prefers to remain in port, except when obliged to provide escorts for supplies and reinforcements dispatched to Libya. If it had not been for the tremendous force which the Luftwaffe concentrated on Malta in recent months, it is doubtful whether Rommel would have been able to renew his strength sufficiently for his recent advance in the Western Desert to have been undertaken.