(a) Belligerent military aircraft may not enter the airspace of Neutrals, except that:
- Belligerent military aircraft in distress may be permitted to enter neutral airspace and to land in neutral territory under such safeguards as the Neutral may wish to impose. The Neutral is obligated to require such aircraft to land and to intern the aircraft and their crews.
- The airspace above neutral international straits and archipelagic sea lanes remains open at all times to belligerent aircraft, including armed military aircraft engaged in transit or archipelagic sea lanes passage.
- The Neutral may permit belligerent military aircraft to enter for purposes of capitulation.
(b) Neutrals must use the means at their disposal to require capitulating belligerent military aircraft to land within their territory, and must intern the aircraft and their crews for the duration of the international armed conflict. Should such an aircraft commit hostile acts, or should it fail to follow the instructions to land, it may be attacked without further notice.
Rule 172 (a) is a specification of the general prohibition laid down in the first sentence of Rule 170 (a). The prohibition for belligerent military aircraft to enter neutral airspace is based on Art. 40 of the HRAW, and it is a necessary corollary to the inviolability of neutral territory.
- Art. 40 of the HRAW, see fn. 771.
- Following the general obligation to render assistance to those who are in distress in the air, a Neutral may allow a belligerent military aircraft in distress to land in its territory. Such permission may not be considered a violation of neutrality by the other Belligerent Party.
- However, the Neutral is not allowed to permit Belligerent Parties the use of its airspace for transit purposes. The Neutral is obliged to require any belligerent military aircraft to land, if necessary by the use of appropriate force. For the duration of the international armed conflict, the belligerent military aircraft and its crew may not leave the Neutral’s territory, and the crew must be interned in order to prevent them from re-engaging in the hostilities.
Rule 172 (a) (ii) safeguards the customary rights of transit passage and of archipelagic sea lanes passage as recognized in Rule 170 (a).
- Entry by belligerent military aircraft into neutral airspace is not prohibited if the aircrews intend to capitulate to the Neutral. Should that occur, the Neutral is under an obligation to intern the aircrews for the duration of the international armed conflict (see Rule 172 (b)).
- Rule 172 (a) (iii) deals with the issue of military personnel giving themselves up. The term “capitulation” used here is reserved for such act taking place vis-à-vis a Neutral. When military personnel give themselves up to the enemy, the expression used in this Manual is “surrender” (see Section S). As to the modalities of capitulation, see Rule 172 (b).
- Capitulation, as required by Rule 172 (a) (iii), must not be abused by turning the Neutral territory into a “base of operations”. Hence, the Neutral must insist on the capitulating aircraft landing within its territory rather than transiting, and must then intern both the aircraft and its crew for the duration of the international armed conflict. The rationale of this Rule is that, if the aircraft or aircrews were allowed to leave the neutral territory, it might re-engage in the hostilities.
- Any act of resistance or deliberate non-compliance is to be considered a “hostile act” and, therefore, sufficient ground for the Neutral to attack the aircraft. In that case, prior warnings or periods of grace are not required.