Report by the British Chiefs of Staff1
Enclosure to C.C.S. 226
Use of Portuguese Atlantic Islands
1. Experience has shown that so long as we can keep even a single aircraft with a convoy during the greater part of each day, the operation of U–boats is greatly hampered. In order to obtain maximum air protection at the present time it is necessary for our convoys to follow a route which not only suffers from the disadvantages of bad weather and ice, but which inevitably becomes known to the enemy. If we take a southerly route at the present time we have to forego a considerable measure of air protection. If we had both a northerly and southerly route which had equal air protection it would be a great advantage and consequently facilities in the Portuguese Atlantic Islands would be of outstanding value in shortening the war by convincing the enemy he has lost the Battle of the Atlantic.
2. The facilities which we particularly require are as follows:
- Facilities in the Azores on Terceira and San Miguel Islands for operating V.L.R. and L.R. aircraft;
- Unrestricted fuelling facilities for naval escorts at either San Miguel or Fayal;
- Facilities in the Cape Verde Islands for operating G.R. aircraft. These, though desirable, are not comparable in importance to a above.
3. The benefits which would accrue from these facilities may be summarised as follows:—
- They would give us a much extended air cover for all
convoys plying between—
- U.S.A. or West Indies and the Mediterranean;
- West Indies and the U.K.;
- South America and the U.K.;
- U.K. and the Mediterranean;
- U.K. and West Africa, and the Cape and Eastwards.
- The increased areas under air cover would give us much greater scope for evasive routing, e.g., when U–boats were concentrating in northern waters, North Atlantic convoys could be routed via the Azores instead of always having to follow the Iceland (C) route.
- Without the Azores we shall always be moving on the outside of the circle while the enemy operates inside it. Air forces there would be centrally placed to cover all varieties of the U–boat campaign against the North Atlantic and Mediterranean theatres.
- We should be able to increase our carrying capacity owing to the possibility of using more direct routes across the middle of the Atlantic.
- We could increase our harassing action against U–boats not only when on passage to and from the Biscay bases, but also while resting, refuelling and recharging their batteries in mid-ocean where hitherto they have been practically immune from interference by aircraft. New detection and attacking devices, which are expected to come into service this spring, would enhance the effect of such action.
- Unrestricted fuelling facilities in the Islands would enable us to make better use of: our inadequate numbers of surface escorts.
- Blockade running between Germany and Japan would be rendered so hazardous as not to be worth the risk.
- German warships and raiders would have greater difficulty in evading detection after breaking out into the Atlantic.
- The islands would prove useful staging points on the air supply routes from U.S.A. to the Mediterranean theatres of operations.
4. We shall clearly have to pay a price and undertake new commitments in order to induce Portugal to give us the facilities in question. The extent of the price and the character of those commitments will depend upon our, and still more important the Portuguese, estimate of the way in which the Axis is likely to react to the transaction. Although we cannot be certain of it, strong reasons can be advanced for thinking that Germany will not, in fact, attack the Iberian Peninsula.[Page 306]
It would, however, be clearly wrong to discount such an attack altogether, and we have, therefore, examined its possibilities. If we assume the worst case, i.e., that the Axis powers would at once make war upon Portugal and attack her metropolitan [and?] overseas territory by all the means at their disposal, the commitments which Portugal would require us to undertake in the face of this possibility would probably include:—
- The defence of Portugal against land and air attack;
- The protection of Portuguese shipping; and
- Assistance in the local defence of Portuguese ports.
5. Of the above, only a calls for detailed consideration. The Portuguese Army is practically negligible and could not, of itself, offer any appreciable resistance. We have made a Staff study of the maximum scale of attack which could be built up against Portugal, with Spain’s acquiescence (which is doubtful), without regard to the possible availability of enemy forces. This works out at 2 divisions ten days after crossing the Spanish frontier, rising to 8 divisions after seven weeks. It is certain that the Germans could concentrate forces overland in Portugal more quickly than we could by sea. To fulfil a guarantee to go to the assistance of Portugal against such a scale of attack we should have to earmark and prepare now between 9 and 11 divisions and some 20 squadrons of aircraft, and hold these forces in readiness together with their shipping. This course could only be followed at the expense of Husky and other future operations in the Mediterranean. Even if this could be done, there would be no certainty that we could protect more than a portion of Portuguese territory.
In the event of the Germans moving into the Iberian Peninsula, our interests would be to cover the Straits of Gibraltar, not to protect Portugal, and this again would be an undertaking we could not hope to fulfil except at the expense of other Mediterranean operations.
If we take the risk of provoking a German invasion of the Iberian Peninsula, even if we consider such an invasion unlikely, we must do so with our eyes open to what the consequences may be. In fact, we may well find that we shall be left without a footing in the Peninsula, except at Gibraltar itself.
6. A base in the Azores would be of particular value during the winter, when the weather in the north frequently interferes with flying. From this aspect therefore, it is desirable to make our approach to the Portuguese sufficiently early to allow the base to be in full working order by the autumn. A particularly favourable moment to open negotiations is now when victory in Tunis is in sight. The Portuguese [Page 307] are less likely to make high demands for protection and the Spaniards are more likely to resist German pressure.
7. Having regard to the fact that we consider Germany is unlikely to invade the Iberian Peninsula, and the tremendous benefits we would gain from the use of the Islands, which are set out in paragraph 3, we feel the risk is acceptable. We therefore recommend that the War Cabinet should authorise an approach to the Portuguese Government now, but no guarantee should be given, and every endeavour should be made to persuade the Portuguese that no threat exists.
- This report was circulated to the Combined Chiefs of Staff under cover of the following memorandum of May 15, 1943, from the British Chiefs of Staff: “The enclosure is a report prepared by the British Chiefs of Staff Committee which is submitted for consideration by the Combined Chiefs of Staff.” For the record of the discussion of this report and the decisions reached thereon by the Combined Chiefs of Staff at their meeting on May 17, 1943, see ante, p. 91.↩