Dear Mr. Magann:

I should like to bring to your attention for the informal consideration of the Canadian Government a question related to the defense of the Sault Ste. Marie Canal and Locks

The vital importance of this waterway to the industrial structure of the continent, and hence to our joint strategic planning in defense of the continent, is I believe quite fully appreciated on both sides of the border. Even if all of the Sault installations were situated in Canada, or in the United States, any threat to their unhampered operation would he of direct concern to both countries, hut the fact that they actually straddle the border makes our joint interest even more obvious.

The Department of the Army (General Staff) has recently completed a staff study on the defense of the Sault, emphasizing its significance, analyzing its vulnerability, and pointing up various conclusions from the military point of view. Based upon that study, the Secretary of the Army, Mr. Royall, has suggested to the Department that informal conversations might he begun with the Canadian Government looking toward prior authorization for United States Federal or National Guard troops to enter and operate upon Canadian soil in the vicinity of the canal and locks if, in a war emergency, such action should become necessary fer the prevention of damage to these installations. The proposed arrangement would, of course, he reciprocal, so that Canadian forces would have the same privilege in regard to the American side.

My first reaction to the problem was that it should come before the Permanent Joint Board on Defense, and that it could not as appropriately be taken up in any other way. It has been pointed out to me, however, that the next regular Board meeting is not until December 1948, and that a firm decision or recommendation would probably not be forthcoming from the Board until the next meeting after that, say in March or April 1949. Considering the importance of the issue, and the disturbed state of world affairs at this time, it has therefore seemed best to make the proposal now. At the next Defense Board meeting, it should be possible not only to discuss the matter, but to hear a report of progress as well.

As the staff study I have referred to goes far to confirm, the most immediate and probable threat to the Sault is deemed to be sabotage. It might take any one of various forms; there would be little or no warning; and it could happen at almost any time. If it should occur, any troops on the site or which might hurriedly be brought there, whether American or Canadian, would need to be able to move as freely and quickly as possible in the vicinity to be effective in the performance of their duty. There might also be duly accredited civilian guards at some future time who would need to have the same freedom of motion in the event of emergency.

Army officers have told me that four of the locks are distinctly on the American side of the line, whereas the fifth lock is in Canadian territory. This fact, if taken by itself, might lead to the conclusion that with sufficient U.S. troops posted on our side, and Canadian troops on yours, there would be no compelling need for either to cross over. That argument is nullified, in my opinion, by the way in which the regulatory works run across the frontier in one piece, as well as a nearby railroad trestle which does likewise. On broader grounds, any such lack of flexibility in the defense plan would be a hazardous condition, and in view of the cordiality of U.S.-Canadian relations, an unnecessary one.

A possible way of handling the problem might be this: to have the appropriate military officer commanding the Sault area on each side of the border empowered to issue orders permitting his troops and/or other accredited guard personnel to cross over during an emergency if requested to do so by the other side, for the specific purpose, of course, of preventing damage to the waterway. If that were agreed to and concurrent orders gotten out, it should be a relatively easy matter for the two nearest local commanders (U.S. and Canadian) to arrange the working details between themselves. One side should not, it seems to me, have to await an engraved invitation via Washington and Ottawa from the other in order to move a short distance across the line if an emergency started to develop or seemed imminent.

If you should desire any further information regarding the Sault defense, such as for example a description of World War II defense arrangements, or an estimate of the joint military strength required to protect the waterway under various conditions, I feel sure that the Department of the Army would be glad to cooperate in making it available to us.

Awaiting your reply with great interest, I am,

Very truly yours,
WILLIAM P. SNOW