In both times of peace and war, USTRANSCOM's role is to provide the Department of Defense with air, land, and sea transportation.

Some of the various missions of the different branches of the United States Armed Forces at the USTRANSCOM headquarters include: Air Mobility Command (AMC) is also located at Scott AFB.

Joint Enabling Capabilities Command (JECC) supervises quickly deployable planning, communications, and public affairs elements.

JECC is located at Naval Station Norfolk, Virginia and is divided into three subordinate joint commands that provide capabilities across seven unique functional areas.

Although the JDA had responsibility for integrating deployment procedures, it did not have authority to direct the Transportation Operating Agencies or Unified and Specified Commanders in Chief to take corrective actions, keep databases current, or adhere to milestones.

They controlled their industrial funds and maintained responsibility for service-unique missions, service-oriented procurement and maintenance scheduling, and DOD charters during peacetime single-manager transportation operations.

The DOD learned much from the deployment to the Persian Gulf, and foremost among those lessons was that USTRANSCOM and its component commands needed to operate in peacetime as they would in wartime.

After the 11 September 2001 attacks, it became a vital partner in the United States' Global War on Terrorism supporting U.S. forces in Operation Enduring Freedom (Afghanistan) and the 2003 invasion of Iraq.

From October 2001 to the present, USTRANSCOM, its components, and its national partners have transported over 2.2 million passengers and nearly 6,100,000 short tons (5,500,000 t) of cargo in support of the war on terrorism.

With the most capable and ready air, land, and sea strategic mobility forces in the world, and with the authorities as the DPO, USTRANSCOM will continue to support the United States and its allies, in peace and war.

USTRANSCOM integrates cyber security language into a majority of its commercial contracts and co-chairs the National Defense Transportation Association Cybersecurity Committee.

The Lockheed C-5 Galaxy fleet is currently undergoing a Reliability Enhancement and Reengining Program modification through April 2018, which will extend service life past 2040.

DP3, in collaboration with Transportation Service Providers (TSP), manages over 550,000 personal property shipments for DoD and USCG customers at an annual cost of $2 billion.

The DPS is a self-service system, offering real-time access for government, industry and customer users to input and retrieve data supporting the entire movement process – from pick-up to delivery of household goods.

[citation needed] Per the National Sealift Policy, USTRANSCOM relies upon the U.S.-flag commercial shipping industry, to the extent it is available, to provide sealift in peace, crisis and war, and the government-owned organic fleets to provide unique national defense capabilities not resident or available in sufficient numbers in commercial industry.

In the past year, fourteen U.S.-flag internationally trading vessels within the VISA program were either reflagged to a foreign country or scrapped without replacement due, in large part, to the reduction in demand.

This loss of U.S.-flag vessels represents a net decrease of over 327,000 square feet of roll-on/roll-off force projection capacity and over 600 U.S. merchant mariner jobs.

Due to the age of vessels in the United States Maritime Administration's (MARAD) Ready Reserve Force, this fleet will begin to lose capacity in the mid to late-2020s, with significant losses in the 2030s.