Paul Costello is a senior program manager for the GMF Cities program, based in the organization’s Berlin office. He leads the program’s City Directors of International Affairs (CDIA) Network, the Cities Managing Migration project, and is involved in several other projects that are part of the GMF Cities democracy work.

Steven Bosacker is Senior Vice President for Innovation and directs the GMF Cities program, which supports local-level policymakers and practitioners in North America and Europe by facilitating the transatlantic exchange of knowledge for building inclusive, sustainable, and globally engaged cities. 

Before joining GMF, Steven was the principal for public sector and partnerships at Living Cities, where he focused on finding and furthering promising practices in large city governments to improve life for low-income residents. The public-sector innovation portfolio included projects such as City Accelerator, Civic Tech and Data Collaborative, and Racial Equity Here, an initiative devoted to implementing racial equity in city government operations.  

Adrienne Goldstein is a Senior Program Coordinator with GMF Tech, focusing on disinformation and social media platforms. She graduated magna cum laude with a B.A. in History from Middlebury College, where she was a member of the Media Portrayals of Minorities Project lab.  

Annika Vollmer is a senior program coordinator based in GMF’s Brussels office. Her main interests span the nexus of inter-institutional security cooperation and climate action, and youth engagement. Annika works for Leadership Programs and coordinates the EU-US Young Leaders Seminar project.

Fluent in German and English, she studied European studies at Maastricht University and holds a master’s in international relations with a specialization in security studies from Leiden University.

Gesine Weber is a fellow on GMF’s Geostrategy team. She works on European security and defense issues, and leads the annual Transatlantic Trends study. Based in Paris, she focuses on Europe’s role as a geopolitical actor, EU defense initiatives, and security and defense policy of the E3 (France, Germany, and the United Kingdom).

Prior to joining GMF, Weber worked as a defense policy adviser in the German parliament and as a consultant for the Friedrich-Ebert-Foundation in Shanghai. Weber is pursuing PhD research on European defense cooperation at the Defence Studies Department of King’s College London, where she is part of the European Foreign Policy Research Group. She contributes to the work of the Centre for Grand Strategy and is an associate researcher for the European Council on Foreign Relations.

Weber holds a master’s degree in European affairs from Sciences Po in Paris and another master’s degree in political science from the Freie Universität Berlin. She studied Mandarin at the Beijing Foreign Studies University. She is regularly published in English, French, and German on European security and defense issues, and is a frequent commentator on European and international media, including BBC, France24, and Deutsche Welle