One month ago, Secretary of Defense Ash Carter sent a stinging letter to Secretary of the Navy Ray Mabus entitled “Program Balance.” The memo offered a stark reminder that Budget Control Act-imposed defense shortfalls will change much more than just the endstrength of our land forces. Secretary Mabus was ordered to re-program the Navy’s 2017 budget to place a higher priority on advanced warfighting capabilities while cutting the number of planned ship purchases by 12, thus curtailing the number of ships available for presence operations. The language used in the memo includes an implicit strategic decision that is about more than just the relative slicing of the budget pie. Carter goes on to say that a combination of higher advanced capabilities and the posturing of the force will be enough to compensate for decreased naval presence around the world. This statement betrays either a misunderstanding of the characteristics of naval presence or a dangerous devaluing of its role in our nation’s overall military strategy. Others, perhaps anxious to defend their own strategic agendas, have promoted Carter’s arguments.

Recently, my friend Cmdr. B.J. Armstrong and I authored a paper for the Center for a New American Security on the topic of naval presence that seeks to improve understanding of its strategic implications and work toward a modern definition of the term. The U.S. Navy has been globally deployed since the late 18th century, providing presence to forward American national interests: from Captain Preble and the Essex in the Pacific and Theodore Roosevelt’s Great White Fleet to Cold War submarine patrols and today’s deployments in the Arabian Gulf. For the past 70 years, the international community has enjoyed a pax oceania that leveraged free navigation and free trade to produce more economic expansion than at any other time in human history. However, recent years have imposed significant pressures on America’s naval presence calculations unlike anything seen in generations. This is largely the result of a change in one of the variables of that calculation: the size of the battle fleet, which has shrunk to the point that the U.S. Navy is no longer able to be persistently deployed.

While the average size of the U.S. fleet in the post-World War II era was around 740 ships, today’s ship count numbers only 273, leaving the Navy unable to keep ships forward deployed to various regions that make up the global maritime environment. If these gaps in naval deployments continue, they will introduce — and arguably have introduced — questions into the minds of local and international actors about the level of U.S. commitment. Such questions invite other rising global powers to attempt to establish new local sets of rules. This is in keeping with certain aspects of a theory that illuminates coming challenges for the United States if it continues down the path of capabilities over capacity.

Power-law theory suggests that the surest way of avoiding high-casualty conflicts is to increase the number of interactions between nation-states during peacetime. These interactions — be they through planned training exercises, port visits, or unplanned at-sea meetings — allow powers to take each other’s measure, delineate their national interests, and demonstrate what they deem acceptable and unacceptable in naval conduct. Persistent interactions allow competing powers to reduce friction slowly, but consistently. Inconsistent interactions allow tensions to rise precipitously and raise the specter of open warfare. To remain forward-deployed and in contact with the challenges presented in the various regions of the globe, the U.S. Navy needs around 350 ships — far beyond the maximum 308 ships that Secretary Carter believes meets “the Department’s warfighting requirements.”

Naval presence is a combination of effect, persistence, and influence. Effect measures the ability of a naval unit to exert immediate impact on the environment around it at any given moment. This definition implies that effect is temporal in nature: It precedes a naval unit’s approach to a given point, has its maximum impact at the moment it occupies the given geographic space, and then declines as the unit moves away.

Persistence measures the ability of the naval unit to remain in the area for a prolonged period of time, retaining sovereign characteristics with minimum demands upon local actors. Persistence derives from numerous contributions: the design of the individual naval units, their fuel and food storage, the density of the fuel involved, the efficiency of their hull-forms, and the strength of the logistics force resupplying ships at sea. Persistence creates the ancillary effect of increasing our knowledge of the local environment, as well as informing local actors of our interests and intentions.

This adds to our influence, which can be broken down into subcomponents of awareness, knowledge, and reach. Influence translates into how far away we can sense the environment around us, how much we truly understand what we are sensing, and our ability to directly change that environment to have it align with our interests. Naval officers (a category which has included Marine officers throughout American history) instinctively understand the character of naval presence — it’s second nature, like breathing — but seldom think about it enough to stop and explain to outsiders. Why should they? They have been doing it for hundreds of years.

There’s good reason to consider the character of naval presence and discuss it openly as part of the national strategic debate: to ensure that presence is understood even by those who do not “breath it.” Secretary Carter’s directive to increase advanced capabilities in the fleet at the expense of the size of the fleet — and specifically at the expense of small combatants which have historically been central to naval operations — ignores the importance of presence and runs counter to the long history of American national strategy. In the end, it will decrease naval presence, allow tensions to rise among local actors, and invite a competition in the maritime environment that has been suppressed for 70 years by constant presence. Historically, these are the very steps that led to war. The commitment of Navy leadership to the construction of frigates, a balanced high-low mix of ships, and a larger fleet overall has demonstrated a deep understanding of the importance of naval presence and a commitment to preserving the pax oceania that has marked the past 70 years of global progress.

The nation’s leadership needs to come back to an understanding of the ideals voiced in the 2007 Cooperative Strategy for 21st Century Seapower, which espoused the American belief that preventing wars is just as important as winning wars. Global competition is the condition — the continuing diagnosis of our day — and naval presence is the prescription. We need to take the prescribed dosage.

Dr. Jerry Hendrix is a senior fellow and director of the Defense Strategies and Assessments Program at the Center for a New American Security. He is a retired Navy Captain and career naval flight officer.

Photo credit: Mass Communication Specialist 3rd Class Erik Foster, U.S. Navy