How can the Pentagon keep pace with Chinese defense modernization amid expected flat budgets? One answer being floated is: “Divest legacy equipment to fund innovative solutions." Public proponents of this approach include two Joint Chiefs, Congress, and the new administration.

But divestment can be unexpectedly difficult. Often the best-laid plans fail in the face of Congressional opposition linked to loss of jobs.

It’s also complicated. Assigning equipment to the legacy category requires agreement on the character, location and type of future conflict. On this topic, even professionals disagree.

And, crucially, timing is always iffy. “Innovative solutions” may not be operational as soon as the planners and strategists anticipate or desire. If you’ve already jettisoned your legacy equipment and the innovative alternative is not yet ready for prime time, you’ve left yourself wide open.

Among other things, a successful divestment strategy requires two key ingredients: a plan to overcome inevitable congressional opposition, and close coordination between the service branches and combatant commanders to arrive at a timeline that retires gear only when an equivalent or better capability is in place.

Anyone who has spent a day in the Washington defense community can rattle off a list of programs the Pentagon tried to kill, only to be stymied by Congressional opposition. JSTARS, the A-10, and the CH-47 Block II are just some of the programs still with us despite the Department’s best efforts to pull the plug.

>>> Congress, Stop Making It Hard To Save Defense Department Dollars

When asked to define “legacy equipment,” a Washington insider once told me: “It’s something made in someone else’s state or district.”

Indeed, linked to every piece of “legacy” equipment in production are jobs, which, in turn, are wired directly to the central nervous system of every Congressional delegation. Cutting active production of a ship, armored fighting vehicle, or jet fighter in favor of investment in a yet-to-be designed AI-equipped robot might sound attractive, but it trades current jobs for an uncertain future.

It’s also worth noting that Congressional opposition isn’t always parochial. Sometimes it acts as a necessary brake on a decision which may benefit just one service at the expense of another or lacks sufficient justification.

Indeed, the Pentagon can rarely carry the divestment day without very careful messaging and working closely with Congress. Several principles should guide those interactions, the first being “no surprises.” When there is a proposed divestment, DOD must identify the affected Congressional delegations and inform them quickly and privately, before word can leak out.

It’s also incumbent on DOD to provide a clear rationale and supporting facts underlying the call for divestment. Ten years ago, I was summoned to brief a member of Congress on why the Army wanted to stop buying a certain truck trailer, of which we already had plenty. I painstakingly laid out how many trailers the Army needed and how many we already had. The congressman was clearly unhappy; it was a tense 20 minutes, lacking all the usual pleasantries. Nevertheless, in the end he had the information he needed to explain the decision to his constituents, and he could also truthfully tell them that he put an Army general through the “wringer.”

Finally, the military should consider how it can mitigate the impact of its divestment decision. Some might consider that outside DOD’s responsibility. However, sometimes a path is available that allows both a divestment to occur and the affected industry to survive. Sometimes replacement programs can be accelerated or workers diverted to product upgrades.

Further complicating divestment decisions is serious disagreement on what even constitutes “legacy.” Army Chief of Cavalry Maj. Gen. John Herr showed an infamous lack of discernment when he declared, “Not one more horse will I give up for a tank.” That was in 1938, just a year before German tanks rolled into—and over—Poland.

Some would sweep tanks in the legacy dustbin, suggesting that future wars will be mostly island-hopping and maritime affairs in the western Pacific to counter China. Tanks have little utility in such operations. Others cite the threat posed by China’s DF-21 and DF-26 anti-ship ballistic missiles to bolster their position the U.S. should never build another Ford-class aircraft carrier. Those arguments were in full play in 2019 when the Pentagon proposed not to refuel the aircraft carrier the USS Truman. Many have sung the swan song for large reconnaissance drones like Global Hawk believing they are unsurvivable in a high-end fight. They may all be right.

Equipped with the luxury of certainty, the Pentagon could construct a military perfectly tailored to win the next war in the precise location it will take place. However, as former Secretary of Defense Robert Gates famously said, “When it comes to where we will use military force next and how, in predicting that we have a perfect record: we have never gotten it right in the last 35 years.”

>>> The Price of Cutting Defense Spending

Tanks and armored vehicles have great utility in Europe and the Middle East. Aircraft carriers and their strike groups pack an immense amount of combat power. Large drones provide unmatched surveillance capabilities for counter insurgency and counter terrorism campaigns. Those who advise a single focus on the Western Pacific could well be prescient. But are we willing to gamble our national security on that prediction? Yes, the National Defense Strategy states that “Long-term strategic competitions with China and Russia are the principal priorities for the Department.” But these are not the only conflicts for which the Pentagon must prepare.

Divesting of legacy capabilities outside those needed for high-end conflict with China could cripple our military efforts in conflicts elsewhere. Any such divestment should be done only gradually, lest we, in the words of Sir Michael Howard, get our doctrine “too badly wrong.”

The final challenge with divestment is the relentless push to divest military capability without its replacement being near. Done right, replacing legacy equipment should be done like a military relief in place, with one capability replacing another without a significant drop in readiness.

That’s how it was done in the mid-1980s, when the Army replaced its 1950s-era M60 tank with the transformational M1s Abrams in Germany. As battalions turned in their old tanks, they were quickly replaced with the newer. No one would have suggested units turn in their old tanks and be satisfied with the promise of an Abrams “in the mail.” Yet with some weapons systems, many today suggest the Pentagon should be comfortable with that approach.

In their 2021 budget, the Air Force proposed divesting a total of 29 KC-135 and KC-10 air refueling tankers in order to free up funds. Of note, they do have a new tanker, the KC-46, in the works. But as of today, it is not operationally useable due to persistent defects. Inconveniently for the Air Force, when Congress asked the commander of the U.S. Transportation Command, Gen. Stephen Lyons his opinion he replied, in essence, “not so fast.” Air refueling, Lyons said, “is one of the most stressed elements in the TRANSCOM portfolio, both for day-to-day operations and for high-end operations.”

With the responsibility to support a conflict that could break out tomorrow, Lyons was not in the position to accept divestment without a replacement. And he shouldn’t. When a divestment is called for, the replacement should be ready—not in the form of a PowerPoint briefing or an uptick in research-and-development spending on a program—but in the form of a tangible capability.

Besides being awkward, public disagreement between a service branch and a combatant commander is avoidable. Once a service has solidified its proposed annual budget request, there is time in the late summer for that branch to brief every affected combatant command on their proposals and to hopefully achieve consensus. The discussion and resulting negotiations should iron out any differences between the services (which invest for the long term) and combatant commands (who are responsible to “fight tonight”).

Divestment of legacy equipment is inevitable and necessary. Without it, our military will collapse under its own weight. Nevertheless, the associated challenges should not be under-estimated, and savings cannot be harvested prematurely.

A plan to overcome inevitable congressional opposition is essential. The services must negotiate their proposed divestments with the appropriate combatant commanders charged with executing operational plans. Without an equivalent or better capability in place, legacy equipment can’t be replaced without introducing yet more risk to an already stressed force.