For the Navy, the size of the fleet is important. But so are its capabilities — a fact that often gets lost in the politically charged debate over how many and what kind of ships the Navy needs to meet its global operational demands.

The Navy’s size became an unexpected point of contention during the presidential campaign. In a nod to hawks within his own party, GOP nominee Mitt Romney said he would boost the number of ships the Navy buys each year from about nine to 15. Romney decried the current size of the fleet — 287 ships, up from 282 in 2008 — during the final presidential debate, comparing today’s Navy to the U.S. fleet in 1917.

Republicans on the House and Senate Armed Services committees, many of whom hail from states and districts with heavy shipbuilding and naval interests, have long made the same case.

“You know, facts are stubborn things,” Sen. John McCain of Arizona, the top Republican on the Armed Services panel, said the day after the debate. “And the fact is that we will have the smallest Navy since 1914 if sequestration takes place.”

In the debate, President Barack Obama famously dismissed Romney’s argument, saying it’s not a game of Battleship.

But the Navy itself has been publicly pushing the idea of a 300-plus ship fleet for years, arguing that it needs that many aircraft carriers, destroyers, cruisers and other vessels on hand to operate and respond to hot spots and emergencies around the world.

The Navy’s solution to reaching that number is the Littoral Combat Ship. The Navy plans to buy 55 of the shore-hugging vessels to counter mines and defeat submarines and fast surface ships. Even after schedule delays and cost hikes that have doubled its price since its inception in 2001, officials insist that the LCS is critical to getting to that magic 300 number.

But many outside defense analysts say they still aren’t clear exactly what role the LCS will play in the fleet. This raises the question of whether the Navy’s plan to have the LCS make up a sixth of the eventual fleet is based more on numbers than on the Navy’s expected missions. While relatively inexpensive at roughly $500 million a ship, it’s still a pricey platform for some of its expected missions, such as mine clearing.

All these decisions come with trade-offs.

“The target to acquire 55 LCS, for instance, means that the Marine Corps will continue operating with 10 fewer amphibious vessels — something it needs for its basic mission function,” Rep. Duncan Hunter, R-Calif., a member of the Seapower subcommittee of the Armed Services panel, wrote in a Nov. 1 Roll Call op-ed.

Of course, if the Navy were to scale back the LCS — something officials would be loath to do after billions of dollars invested in the program — the service would need to develop another low-cost ship it could buy in bulk in order to meet its strategic and fleet-size goals.

Adm. Jonathan W. Greenert, the Navy’s top officer, has launched a high-level council to re-evaluate the program and said Nov. 16 that the LCS “is still a program that is coming into its being.”

Greenert also made clear that he isn’t exclusively driven to reach a certain fleet size.

“It’s not just the number of ships,” he said. “It’s the number of ships forward, and at what type, and what capability for what mission around the world.”

Still, comparisons to fleets of the past continue. For example, House Armed Services Chairman Howard “Buck” McKeon of California and Senate Armed Services Seapower Subcommittee ranking member Roger Wicker of Mississippi have both warned that the budget cuts set to be triggered in January under the sequester would result in a 230-ship fleet, making it the smallest Navy since World War I. The Navy had 231 ships in 1915 — a number that jumped to 774 ships by the end of the war.

But patrol boats made up nearly half of the fleet in 1918. Fleet carriers were not introduced until 1924. Today’s Navy, by comparison, has 11 nuclear-powered aircraft carriers. The Navy of 1918 boasted 80 submarines, but they were far less capable and lethal than the 71 nuclear-powered subs in the modern fleet.

“Using ship count as a metric over very long periods of time — going back over 90 years ago — that’s deeply flawed because you’re comparing ships that have vastly different capabilities,” said Todd Harrison, an analyst at the Center for Strategic and Budgetary Assessments.

Counting ships, Harrison added, should be only one of many measurements of the Navy’s effectiveness. “What you want to get to is what are the capabilities you want in your Navy,” he said.

Republican Rep. J. Randy Forbes of Virginia, a senior House Armed Services member, however, argues that comparing ship numbers over the years provides a historical reference for tracking trends in the size of fleets.

“It’s fair to show the direction that we’re going,” he said. “Sometimes you need touchstones to show those directions.”

Forbes and other hawkish Republicans on the Armed Services panel, including fellow Virginian Rob Wittman, acknowledge that size isn’t the only way to measure the Navy’s might. But, they say, it’s an important metric and should be weighed along with the specific makeup of the fleet.

“Quantity is a quality all its own,” Wittman quipped.