The US Treasury sanctioned senior Muslim Brotherhood leader Mahmoud al-Abyari and others for allegedly supporting Hamas through charities, businesses and underground banking networks. The move reflects a broader global strategy to disrupt terrorist financing by targeting leadership, funding channels and financial intermediaries while strengthening international cooperation.

International efforts to confront transnational terror networks have entered a new phase targeting the leadership centers responsible for managing, financing and coordinating the structures that enabled their operations across multiple countries.

The US Treasury’s July 23 action against Mahmoud al-Abyari, a senior Egyptian Muslim Brotherhood leader based in the United Kingdom, is a case in point. Authorities designated al-Abyari alongside three individuals and three entities it accused of providing material support to Hamas, describing a “multi-layered typology” in which Muslim Brotherhood affiliates and Hamas-directed front organisations used charitable structures and underground banking networks to move and disguise funds across jurisdictions.

The targets occupy different positions in that alleged architecture. Al-Abyari, whom authorities identified as secretary-general of the Muslim Brotherhood, was accused of supporting fundraising for two previously sanctioned organisations that Washington links to Hamas. Treasury separately identified two fundraising charities and a Türkiye-based company that it said transferred hundreds of thousands of dollars for Hamas and provided underground banking services involving both conventional currency and cryptocurrency.

The significance is therefore less about one senior figure than about the connections Treasury says link leadership, fundraising and financial intermediation across countries. US Treasury Secretary Scott Bessent said the administration would pursue those enabling Hamas “under the guise of charities, businesses, or underground financial networks.”