The National Defense Strategy calls for the U.S. military to continue rebuilding, especially as it adapts to respond to the new era of great power competition. It must be done, but it won’t be easy. There is no direct road leading to both goals. And then there’s the matter of money.

The Trump administration’s budget request gets many things right, but there are areas where Congress can — and should — improve on the proposal.

It starts with the overall dollar amount. The administration’s request of $750 billion aligns with the needs outlined by former Defense Secretary James Mattis. His recommendation for annual Pentagon budget increases of between 3 and 5 percent above inflation were subsequently endorsed by the bipartisan National Defense Strategy Commission. Their estimates are that Pentagon funding at that level should be enough to maintain our military’s current competitive advantages over peer adversaries.

So, the president’s topline number for defense is fine. But how he gets there isn’t. He proposes limiting the base defense budget to $576 billion — the cap established in the Budget Control Act of 2011. The rest of the money would come from the Overseas Contingency Operations (OCO) account. It is a shortsighted way to budget for defense. OCO resources are only fully available for the current year, whereas planning for modernization requires multi-year commitments. Additionally, tapping the OCO for planned defense projects completely distorts the reason the fund exists, which is to fund actual emergencies.

In addition to considering where defense funds should be cached, lawmakers need to take stock of where the Pentagon is on the road to rebuilding and preparing for the future.

In the past two years, the Pentagon has made considerable strides in restoring military power highly leveraged by over 15 years of continuous warfare. It also has made significant improvement in readiness levels. The Army, for example, now has 15 brigades rated as combat ready, versus only 10 ready brigades two years ago. In this area, it is a matter of maintaining the emphasis and letting the changes take place in the military.

On the great power competition front, two things are worth highlighting: the Space Force and the Army modernization. Creating a Space Force will help the country and the military focus on what it takes to maintain space dominance. It also will enable the United States to concentrate its space assets and sharpen Pentagon thinking on how to tackle the challenges of space.

After years of cancelled programs, the Army finally is conducting a rigorous review of how it modernizes its forces. The review is guided by six priorities for entering the new era of great power competition and the need to establish an Army Futures Command. Army leadership started showing its cards in this budget request by shifting money from legacy programs to research and development. These are welcome steps.

There are, however, two negative elements worth highlighting: the planned purchase of F-15X and the too-early retirement of the USS Truman. Since 2002, the Air Force has purchased only fifth-generation fighters. The budget proposes buying eight F-15X, a fourth-generation fighter, in 2020 and another 72 in the next five years.

In other words, the Air Force proposes investing nearly $8 billion in fighters that can’t even survive today’s contested environments of great power competition, much less tomorrow’s.

The Navy, on the other hand, proposes to cancel the refueling overhaul of the Truman, taking the aircraft carrier out of service more than 20 years before it’s time. The move would save only $16.9 million in 2020 and runs counter to the Navy’s goal of growing to 355 ships, much less its intent to purchase two carriers at once. Lawmakers would do well to demand the rationale for this major reduction in the nation’s ability to project power.

These are just some of the issues that make this an extremely challenging budget cycle for defense. The 2020 defense budget sits a crossroads for the current National Defense Strategy. If Congress and the Pentagon are to give any weight to the great power competition described in the strategy, they must do it in this budget. Our allies and our adversaries are watching to see if Washington will back its words with funding.