Igor Makarov, a billionaire holding Moldovan and Cypriot nationality, has filed a USD 350 million ICSID claim against Canada under the Canada–Moldova BIT. The claim challenges the freezing of his assets under Canada’s Special Economic Measures (Russia) Regulations, alleging unlawful expropriation and breach of fair and equitable treatment. This is one of the first major ISDS challenges to modern sanctions frameworks. It forces tribunals to decide whether national security and foreign-policy determinations should override treaty-protected property rights. A ruling for the investor could significantly increase litigation exposure for states aligning their sanctions policies with international allies, chilling the use of asset-freeze measures as an instrument of collective security. The case intersects with issues analysed in the IISD paper on sanctions and investment treaties, which warned that BITs concluded before Russia’s 2022 invasion create latent litigation exposure for sanction-aligned states.