Memorandum from Joseph P. Walshe to Eamon de Valera (Dublin)
with covering note from Joseph P. Walshe to Kathleen O'Connell (Dublin)

[handwritten insertion by Walshe]

So far as we know no neutral Government has made a general public declaration of this character, and no doubt, for good reasons.

In any case I think the Taoiseach does not intend to make any.

Internment of Belligerent Aircraft and Airmen

What answer should be given to the question 'Why are you not interning all planes and all crews?'.

1. The air warfare rules formulated in the Hague in 1923, though not in force as a Treaty or a Convention, serve as a guide for the general practice of neutrals. These rules declare that belligerent aircraft are forbidden to enter the jurisdiction of a neutral State. The neutral Governments must prevent them entering, but, if such aircraft do enter, they must be interned.

2. The present war has brought an enormous increase in the number of aircraft used by belligerents, and with that increase neutral Governments have been presented with new and serious problems. It has been found by experience that strict adherence to the Hague rules would impose too great a burden on the neutrals whose geographical situation makes them particularly liable to constant accidental overflying. Hence the custom has grown up in countries so situated to make certain exceptions to the rules about internment. Transport planes are not usually interned. Neither are training planes. Indeed, from the practice of neutral Governments, not always easy to discover during the period of belligerency, the custom is slowly emerging of confining internment to planes and crews actually engaged on a strictly operational flight. Naturally, special problems frequently arise which have to be decided in the special circumstances of each case, and one group of neutrals may have difficulties which never arise for another. It is clear, for instance, that Sweden, Switzerland and Ireland are faced with difficulties which are not experienced by the other European neutrals. And the European neutrals as a whole afford little basis of comparison with neutrals situated far from the theatres of war. Each Government is doing what it can within the framework of its special difficulties to build up a body of rules or customs based on the broad principles of international law. The fundamental principle is, of course, that Neutrals must not do anything which could be interpreted as taking part in the war.

3. Notwithstanding relatively minor divergences in practice, it will probably be found after the war when new rules come to be framed that the experience of the European neutrals will have led them to adopt a more or less common attitude in relation to the general problem of belligerent aircraft.