Russian President Vladimir Putin’s failure to rapidly defeat a much smaller foe is not just a failure of strategy, but an overestimation of his military’s capability, training and prowess. U.S. leaders need to take a hard look in the mirror and question whether we are treading similar ground with a set of military capabilities too small and too old given current threats.

American leaders are fond of saying ours is the best military in the world. They fail to realize that key elements of our forces have shrunk by half since our last clear-cut victory: 1991′s Operation Desert Storm. Furthermore, the U.S. has been unfocused on great power competition for over three decades as it overprioritized and overspent on counterinsurgency operations.

This means the United States is less able to deter conflict and fight to win if necessary. That is one reason why Putin felt emboldened to invade Ukraine. He sensed weakness in U.S. and NATO forces, and pressed forward with his aggression. We see the Chinese making similar calculations in the Pacific by seizing and militarizing neutral territory and flaunting international norms without an adequate U.S. response; freedom of navigation missions won’t cut it.

This should be a wake-up call to rebuild the U.S. military.

The threat of sanctions did not deter Putin, nor did Europe’s newfound unity change his mind. Diplomacy that is not backed by military might will fail. It all comes down to credibility behind the words. The U.S. has lost its edge in that regard from both a military capability and capacity perspective.

The choices Putin made with respect to his military’s force structure left him with the wrong force design and poor readiness for the war he chose to fight. Likewise, the choices the U.S. has made in recent years — and the ones it makes today — are inadequate to the challenges posed by its competitors.

Nor will we be able to build needed military power once the enemy triggers a tripwire. Today’s world moves too fast and is too complex to allow for a reactive buildup. F-35 fighter jets, B-21 bombers and Virginia-class submarines, plus their highly trained crews, do not manifest overnight. Unless we make the right defense choices today, there will be no time to recover when an adversary requires us to fight.

President Joe Biden’s fiscal 2023 defense budget plan steers America down the wrong path. Rather than reversing America’s 30-year decline in defense capability and capacity, it accelerates that decline. With inflation properly included, defense funding goes down from last year.

Defense News convened with defense community thought leaders and experts to break down the fiscal year 2023 budget.

The effects of the proposed defense budget are corrosive. Consider that the Air Force is currently the oldest, smallest and least ready in its history. The FY23 budget plan calls for it to retire roughly 1,500 aircraft over the next five years while buying only 500 replacements. That reduces it a further 25%.

The Navy is set to shed 24 ships over the same period. In FY23 alone, the armed services combined are reducing personnel by 25,000. This is a recipe for disaster, not only for the United States but for Western democracies in general.

Unless the United States and its allies can achieve the strength necessary to defeat both Chinese aggression in Asia and Russian aggression in Europe in near simultaneous time frames, we cannot hope to deter our rivals.

However, defense leaders across multiple administrations, driven by budget concerns and nondefense priorities, have abandoned this approach. They now plan for wars to occur one at a time. Reality likely will not work like they expect. The only thing we will 100% achieve is not accurately forecasting the future. The ability to only handle one war at a time incentivizes our opponents — China, Russia, North Korea, Iran and a broad range of nonstate actors — to strike when we are consumed by the first crisis.

War is always more costly and devastating than maintaining the peace; witness the devastation in Ukraine. The cost of weakness is a bill we cannot afford to pay.

Germany and Japan get this. They understand the threats on their doorsteps, and that is why they both declared their intent to double their defense budgets. Their resolve to reinvest in their own defense reflects the pragmatic realization that only through investment and preparation can they hope to ward off those threats.

The United States does not need to double its defense budget, but it does need to reverse the decline in its capacity and capabilities to credibly deter and, if necessary, defeat both China and Russia simultaneously. Only then will we be able to deter those fights from occurring.

Retired U.S. Air Force Lt. Gen. David A. Deptula is dean of the Mitchell Institute for Aerospace Studies and a senior scholar at the Air Force Academy. He helped plan the Desert Storm air campaign, commanded no-fly zone operations over Iraq and orchestrated air operations over Afghanistan.

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