The international legal regime governing attacks on nuclear facilities is a subject beyond my expertise. But here’s an excerpt from the 1981 UNSCR adopted in response to Israel’s attack on the Osirak reactor (I am using the Osirak spelling because the CIA does):

3. Further considers that the said attack constitutes a serious threat to the entire IAEA safeguards regime which is the foundation of the non-proliferation Treaty;

4. Fully recognises the inalienable sovereign right of Iraq, and all other States, especially the developing countries, to establish programmes of technological and nuclear development to develop their economy and industry for peaceful purposes in accordance with their present and future needs and consistent with the internationally accepted objectives of preventing nuclear-weapons proliferation;

5. Calls upon Israel urgently to place its nuclear facilities under IAEA safeguards;

6. Considers that Iraq is entitled to appropriate redress for the destruction it has suffered, responsibility for which has been acknowledged by Israel;