751G.00/6–1054: Despatch
The Chargé at Saigon (McClintock) to the Department of State
No. 579
Subject:
- Alleged presence of Soviet or Chinese Submarines in the Gulf of Tonkin
More for the record of the Department than with intent to convey news, I desire to report that only today the Embassy Naval Attaché informed me that fairly reliable indications had been received in April and early May of the presence of either Soviet or Chinese submarines in the Gulf of Tonkin. The Naval Attaché had of course, by his own channels, reported these facts to the Department of the Navy as they materialized.
According to the French naval staff in Saigon, it was learned from a radio intercept of a Viet Minh message that between six and eight Soviet submarines were operating in the Gulf of Tonkin based on Hainan Island. This was in the latter half of April.
Independently, at the end of April and early May, United States sources established radar contact with unidentified submarines in the Gulf of Tonkin. Three of these radar sights were made by aircraft in the last week of April and another sight was made by radar from an American freighter plying in the Gulf of Tonkin, which was challenged at night by blinker from one of two submarines, one lying off the port beam of the freighter and the other on the starboard quarter. The blinker signals were clumsily given and therefore it can be surmised that the submarine was of Chinese Communist registry.
It is not impossible in my estimate that the radio intercept reporting eight Soviet submarines in the Gulf of Tonkin was a cover and deception maneuver by the enemy designed to intimidate the French from more resolute action in the defense of the Tonkin Delta. Certainly the waters of the Gulf of Tonkin, by virtue of their shallow depth, are ideal for mining, and the French naval capability in the Far East to counteract such measures is exceedingly limited. Furthermore, the French naval forces Far East have had very little experience in ASW, the crews are untrained, and the vessels, with the exception of two DE’s, are not fitted for hunter-killer operations. The French naval air arm, however, with its Privateers, should be in a position to render more effective opposition to a submarine campaign than the French surface fleet.
Since apparently the freighter radar sighting of May 5, when it was challenged by an unidentified submarine, is an authentic incident, it would seem to me that this likewise might be part of an over-all cover and deception maneuver since, if in fact either the Soviet or [Page 1680] Chinese Communist navies seriously intended to mine the Gulf of Tonkin, they would do so secretly.
My estimate is strengthened by the coincidence of dates, since the intercepted radio message and the sighting of unidentified submarines came at a time when the French Government was endeavoring to make up its mind whether or not to defend Tonkin. In consequence, it would have been an obvious maneuver for the enemy to seek to shake French determination in this regard and to endeavor to establish the spectre of a submarine menace to the line of communications to Tonkin and the Haiphong evacuation perimeter.