WASHINGTON — America’s investments in military readiness are paying off, particularly for the Army, but its armed forces would be stretched dangerously thin if they participate in more than one large war at the same time.

That is the conclusion of the Heritage Foundation’s “2020 Index of U.S. Military Strength,” the think tank’s annual review of the past year’s defense policy issues. The Index assesses the global operating environment and U.S. military strength. It ranks all topics on a five-tiered scale of “very weak,” “weak,” “marginal,” “strong" and “very strong.”

This year’s index is the rosiest of the six that the Heritage Foundation — seen as influential on the Trump administration and congressional Republicans — has issued. Defense News was given an exclusive interview with Dakota Wood, a senior research fellow at the think tank who edited the 500-page report. The full document was released Oct. 30 and can be read here.

The Defense Department spent the last year “really focused on readiness. It reflects the services getting serious about that,” Wood said. “The services have gotten very serious about regaining these lost conventional combat sorts of skills and are also starting from a fairly new base [of troops], and rediscovering things that the Cold War force knew out of habit. And you're doing that in a budget environment that is less helpful than what it needs to be, so I think the increase in readiness is a positive sign.”

However, America’s military still falls short of the ability to fight two major wars at the same time, with Wood calling it “basically a one-war force.” Wood praised the efforts of the Army and Marine Corps to transform themselves to face both a great power competition and a tighter budget environment, but said America must still address existing vulnerabilities.

“Our bigger message in the index is saying to the nation as a whole, and to Congress as its representatives, that we are not devoting the resources needed for the U.S. to be a credible player in the global world against more than one major competitor,” he warned.

Service improvements

The report judges each service in three categories — capacity, capability and readiness — before offering a final score. Overall the report ranks each of the four services as “marginal,” essentially a “C” grade. That’s an improvement for the Marine Corps from the previous year, when it was were ranked “weak” largely due to concerns about aviation readiness.

The most notable change in the rankings is the move of Army readiness from “strong” to “very strong,” the highest rank for any of the armed services. Readiness for the Air Force and Marine Corps each moved from “weak” to “marginal,” while the Navy stayed flat. None of the services lost ground compared to the 2019 report.

The Army’s readiness improvements come in the wake of what the report calls “significant” investment in building out brigade combat teams, or BCT. The service went from having 15 of its 35 BCTs at an acceptable level of readiness in the last index to 28 BCTs at an acceptable level of readiness in the 2020 index — a dramatic improvement driven by what Wood described as focused investments by Army leadership.

“The Army is focused on getting their brigade combat teams to the national training centers. It’s just dramatic,” Wood said. Meanwhile, the Marines have “really put a lot of money against improving their aviation readiness rates.”

Still, the services all fall well behind what Heritage believes is needed for two simultaneous major conflicts. The report calls for an Army of 50 brigade combat teams, a Navy of 400 ships, an Air Force of 1,200 fighter/attack aircraft and a Marine Corps of 36 battalions.

However, Wood acknowledged that those figures might be impossible to meet in light of the “political reality” of increased defense budgets, especially as the nation faces an election and a trillion-dollar deficit.

“The focus of the services on current readiness is understandable because they can do that within the authorities and monies they have,” Wood said. “Expanding the force seems to be a bridge too far, and modernizing the force with all the new equipment you need to be able to conduct operations” would take long-term investments that are likely out of reach.

“There is a difference in acknowledging the reality of that and being supportive. Acknowledging the reality of the service’s challenges, I understand why they are making the decisions and I really can’t fault them for it,” he added.

On the nuclear side, the U.S. has seen noted improvement, with warhead modernization and the nuclear weapons complex receiving an upgrade from “weak” to “marginal,” largely due to increased budgets for the often-underfunded National Nuclear Security Administration.

Force readiness also moved from “marginal” to “strong,” as results from years of efforts to improve morale and manpower in the nuclear forces has begun to pay off.

Regional and fiscal realities

On the whole, the authors of the index conclude that the threat to U.S. interests from abroad remains “high,” as America faces challenges from the “4+1 threats” — Russia, China, North Korea, Iran and terrorism.

Those threats remain similar in capability and aggressive behavior to the previous report, with one change: Heritage says the threat of terrorism from the Middle East has dropped since the collapse of the Islamic State group’s physical caliphate.

Though Iran dominated the news throughout the summer, with the U.S. minutes away from striking Iranian military targets, the index did not move up Iran’s threat rating. “Iranian influence actually increased, just because they’re more mature through Iraq and into Syria,” Wood said, but “the Yemen war, a bit of a proxy war between Saudis and Iranians, kind of settled somewhat. It’s just not as news-capturing; it’s this ugly kind of stasis that it’s currently in.”

Russia and China were already ranked as the highest capability on Heritage’s scale, and so had no room to move up, but both nations continued to improve their respective capabilities, according to the report. And capacity remained an issue, as Russia and China have massed their respective forces in particular regions while the U.S. attention is spread across the globe.

Given the expected future fiscal environment, Wood said, the Pentagon should consider difficult choices and gamble on which competitor is more likely to evolve into a military foe.

“The fiscal realities say the United States really can only seriously think about one major war,” Wood said. “So pick your opponent. Is it a war against China, or a war against Russia? Because if I’m going to focus on China, that’s a different Army. If I focus on Russia, it’s a different Marine Corps and Navy.”

Those fiscal realities may quickly hit home, as Congress appears headed for a stopgap spending plan that could be needed into February or March. Under a continuing resolution, or CR, the military would be barred from launching new programs, and funding would be locked at the previous year’s level.

A six-month CR might drop capability in Heritage’s rankings, which weighs the age of systems, Wood said.

“Right now, the average Air Force fighter aircraft is 28 to 29 years old. If that gets to 29 to 30, because [the Defense Department] is not replacing or buying new gear, that number can bump across the threshold which our scoring system tips from ‘marginal’ to ‘weak,’ ” he said. “ Also you can see some losses in capability because of continued aging and questionable health of modernization programs because those programs are not getting the funding they need to stay on track.”

If Congress’ inability to navigate an election year and a contentious impeachment process yields an extended CR, Wood expects to see the services continue their focus on capacity at the cost of modernization.

“I don’t believe the services will shrink because manpower is a fixed cost and the people I have are the people I have,” he said. “The additional training needed for this increase in readiness is less expensive than trying to start a new multibillion-dollar acquisition. And so I think within the services, if it’s a yearlong CR, they will claim to continue with their focus on readiness.

“Again, if I have a small force, I have to make sure that at least it is ready for combat."

Aaron Mehta was deputy editor and senior Pentagon correspondent for Defense News, covering policy, strategy and acquisition at the highest levels of the Defense Department and its international partners.

Joe Gould was the senior Pentagon reporter for Defense News, covering the intersection of national security policy, politics and the defense industry. He had previously served as Congress reporter.