Biden signed and order today authorizing the Pentagon to send up to 3,000 military reservists to Europe for active duty:

Here’s the actual order from the White House website:

Ordering the Selected Reserve and Certain Members of the Individual Ready Reserve of the Armed Forces to Active Duty

By the authority vested in me as President by the Constitution and the laws of the United States of America, including sections 121 and 12304 of title 10, United States Code, I hereby determine that it is necessary to augment the active Armed Forces of the United States for the effective conduct of Operation Atlantic Resolve in and around the United States European Command’s area of responsibility. In furtherance of this operation, under the stated authority, I hereby authorize the Secretary of Defense, and the Secretary of Homeland Security with respect to the Coast Guard when it is not operating as a service in the Navy, under their respective jurisdictions, to order to active duty any units, and any individual members not assigned to a unit organized to serve as a unit of the Selected Reserve, or any member in the Individual Ready Reserve mobilization category and designated as essential under regulations prescribed by the Secretary concerned, not to exceed 3,000 total members at any one time, of whom not more than 450 may be members of the Individual Ready Reserve, as they deem necessary, and to terminate the service of those units and members ordered to active duty.

Here’s some reaction to the order: