America’s Navy sails alone.

It’s impossible to compare the U.S. Fleet to the rest of the world’s navies, because the United States has a singular role and mission. We need a better navy than anyone else.

No post-World War II President has backed away from the nation’s expansive leadership role. Nor has any recent President significantly reduced its foreign policy commitments by treaty or interest. In fact, the number and scope of U.S. military missions has expanded in the past 15 years.

As long as the United States undertakes a comprehensive role in guiding the international order toward peace and freedom, the nation’s leaders must sustain the power necessary to accomplish that mission.

Yet America’s military does more than fight. It also provides the underpinning for the nation’s soft-power tools by supporting sanctions enforcement and strengthening diplomatic negotiations.

Because U.S. economic growth is connected to the stability and prosperity of the global economy, the nation uses its naval capabilities to guarantee sea trade. That ends up protecting virtually all maritime assets.

Secretary of Defense Robert Gates claims the United States possesses “massive” and “significant” naval overmatch on, above, and below the high seas. But our traditional lead is shrinking. Many of today’s major platforms were bought during the Reagan defense buildup of the 1980s.

All military advantages are fleeting. Maintaining an edge requires robust and purposeful investment. Today’s U.S. Navy is the smallest in fleet size since 1916. The average age of the Navy’s battle force is approaching 20 years.

How we invest in hard power affects our national-security interests. Last year, Australia announced its biggest military buildup since World War II in response to the changing regional security environment. It specifically cited declining U.S. supremacy in the Pacific Ocean and China’s rapidly growing navy.

The United States should not only prepare for the full array of risks, but also maintain substantial safety and technological-superiority margins. Seeking to have “just enough” of any core defense capability would be foolish. Planning is never perfect, but the cost of being too strong is far less than the cost of weakness. In the long run, supplying sustained and predictable funding to the military and providing for regular upgrades is far more cost-effective than allowing the force to become hollow and then rebuilding it.

In his May speech to the Navy League, Secretary Gates highlighted the growing disconnect between defense capabilities and spiraling costs of new systems, citing the DDG-1000 as the poster-child program gone awry. A primary reason military equipment is becoming more expensive is that it is getting better and more technologically advanced. Yet policymakers cannot ignore the culprit of dwindling defense modernization economies-of-scale. The cost of the Zumwalt dramatically increased after the Navy changed the program requirements and schedule several times and slashed the build rate from 32 to “8 to 12″ to 7 to finally just 3.

Gates presented a false choice of superior, advanced platforms or the need for quality leaders. Both are required. Adversaries are choosing to invest in asymmetrical weapons and advantages to oppose the United States, but these investments shouldn’t be an excuse for the Navy to abandon its blue-water capabilities.

Taken together, the current and coming cuts to next-generation systems would further reduce the traditional margins of the U.S. military-technological edge against defense investments by other countries. That doesn’t mean the United States necessarily would be fighting some peer competitor that today may not be on the radar. Rather, what Washington chooses to invest or not invest in will provide incentive for others to build up where the United States is pulling back.

As militaries expand and modernize, the probability of miscalculation grows. Military weakness, real or perceived, encourages enemies to act. Threats to the global system of trade would increase. This delicate system would become more vulnerable to attempts to disrupt access to vital resources.

Naval-modernization cuts could increase the likelihood that U.S. military capabilities will fall short of the nation’s wide-ranging security commitments. Current budget plans indicate the United States may relinquish its military superpower status, not to another nation per se, but by reverting to a position where the country lacks the capacity to engage and maintain a forward presence globally.

Less military investment might save money in the budget today, but it’s a change we can’t afford in the years ahead.

Cross-posted at the U.S. Naval Institute