Which MAGTF is a mid-sized organization that conducts significant security operations?

The Marine Expeditionary Brigade (MEB) is correctly identified as a mid-sized organization that conducts significant security operations. The MEB is a scalable, versatile force that can rapidly deploy and execute a variety of missions, including security and stability operations, humanitarian assistance, and disaster relief. With its combination of ground, air, and logistical components, it is structured to perform a range of operations with sufficient capability and command and control capabilities.

Additionally, the brigade is designed to operate independently or as part of a larger Marine Corps force, allowing it to be a critical component of the Marine Air-Ground Task Force (MAGTF) structure. Its size and organization enable it to engage effectively in medium-scale conflicts and provide necessary support to coalition operations, making it integral to U.S. military strategy regarding regional and global security operations.