To amend the Homeland Security Act of 2002 to authorize international cooperative activities to strengthen efforts relating to countering violent extremism, and for other purposes.

Allies Countering Extremism Act or the ACE Act This bill amends the Homeland Security Act of 2002 regarding the promoting antiterrorism through the international cooperation program to allow France and Germany to be included as foreign partners. The bill authorizes the Department of Homeland Security, in coordination with the Department of State and appropriate federal officials, to enter into cooperative activities with foreign partners to strengthen efforts relating to countering violent extremism. Such activities may include: (1) efforts aimed at improving counter-radicalization and counter-messaging methods, and (2) recommendations for incorporating any new findings into national policies for countering violent extremism.