A Government Accountability Office look at readiness indicators found ground forces—the Army and Marine Corps—have improved while sea forces have declined.

The congressional watchdog agency looked at changes in resource readiness and mission capability rates from fiscal 2017 through fiscal 2021. Ground forces were the only area to show improvements in both categories.

That does not mean the Army was perfect. The report finds shortfalls in rail support for moving Army equipment in training for operations in environments with contested mobility. The Army and Marines also need to do more to prevent tactical vehicle accidents, the report says.

GAO investigators expected to find readiness gaps. “Nearly two decades of conflict has degraded military readiness,” the report says. “To maintain the U.S. military’s advantage across all domains in a new security environment characterized by great-power competition, DoD is working to rebuild and restore readiness while also modernizing its forces.”

Rebuilding readiness is not simple, the report says. “DoD's readiness rebuilding efforts are occurring in a challenging context that requires the department to make difficult decisions regarding how best to address continuing operational demands while preparing for future challenges,” it says.

The Army requires rail transportation to move about 67% of unit equipment for overseas deployments. This is a big task. A 2020 simulation to move equipment from just one installation in support of large-scale combat operations showed it would take 2,200 rail cars over three days. It would take 600 rail cars to move one armored brigade combat team.

Additionally, it is not clear whether all the rail tracks needed for such a big movement are in good condition, the report says. There are also concerns about whether there are enough rail crews to conduct major movements.

The report recommends the Army take a closer look at the condition of rail lines and the availability of trained rail crews.

The full GAO report is available here.