Dr. Ariane Tabatabai, Middle East Fellow at the Alliance for Securing Democracy at the German Marshall Fund of the United States, is back on Press the Button to discuss the recent assassination of Iranian nuclear scientist Mohsen Fakhrizadeh, and how this could affect US-Iran relations as President-elect Joe Biden prepares to take power. Early Warning features Laura Grego of the Union of Concerned Scientists analyzing the recent US missile defense test that successfully intercepted an intercontinental-range ballistic missile (ICBM) target, and what it means for future arms control efforts and US relationships with other countries that possess ICBMs.