Part 2
Domestic Jurisdiction in ICC Offences
Section 12.—
(2) Subsection (1) also applies in relation to a person of any other nationality who does an act outside the State that, if done within it, would constitute both—
(a) a war crime under sub paragraph (a) (grave breaches of the Geneva Conventions) or (b) (other specified serious violations of the laws and customs applicable in international armed conflict) of Article 8.2, and
(b) an offence under section 3 (grave breaches of the Geneva Conventions and Protocol I thereto) of the Geneva Conventions Act 1962.
(3) An act which—
(a) is done outside the State on board an Irish ship or Irish controlled aircraft, and
(b) if done within it, would constitute an ICC offence,
is deemed for the purposes of this Act to have been done within the State.
Territorial jurisdiction - national proceedings
EDIT.