Remember President Barack Obama’s “pivot to Asia”? In 2012, then Defense Secretary Leon Panetta announced the Navy would put about 60 percent of its forces in the Pacific.

Seven years later, the pivot is complete. But is it enough to protect vital American interests in the region?

The U.S. Navy Pacific Fleet comprises more than 170 vessels. They’re responsible for a vast maritime area of operation—one that spans almost forty-eight million square miles. Not everyone in the pool plays nice. Russia, China and North Korea splash in the same waters.

And not all of our ships are in the western sector. Only the Seventh Fleet is forward deployed, and as of June 17, it had only fifty-seven warships. The remainder of the Pacific Fleet is located in Hawaii, California and Washington state.

Compared to Chinese and Russian naval forces in the region, the United States enjoys superior training and a technological advantage. They are, however, vastly outnumbered.

China boasts 182 submarines and ships of corvette-size or larger; Russia’s eastern fleet has twenty-seven submarines and surface ships. Although we do not envision Beijing and Moscow operating together, their combined Pacific naval forces outnumber the Seventh Fleet by a four to one ratio. If smaller vessels such coastal missile patrol craft and mine warfare ships are included, then the “other side’s” tally grows by another 156 ships. And that doesn’t include the almost 450 paramilitary Chinese coast guard vessels.

In event of a crisis, the United States would bring more force to bear by deploying ships and submarines from Pearl Harbor or its west coast bases. But it would take time for them to arrive on the scene. For example, it takes approximately fourteen days to reach the South China Sea from Pearl Harbor, and almost one month for a carrier strike group to arrive from San Diego. That kind of delay can be deadly.

Clearly, the Navy needs to increase its presence and reduce the response time of naval forces in the critical Seventh Fleet area of responsibility. But how?

Transferring more warships from the Atlantic to Pacific Fleets is not the answer. The Pacific Fleet already commands 60 percent of our naval forces, and we must protect our critical interests elsewhere as well.

Nor can the Pentagon snap its fingers and conjure up additional ships overnight. U.S. shipbuilding capacity and federal budget constraints will limit the ability to significantly increase Navy shipbuilding in the next ten years. Meanwhile, the U.S. attack submarine force will decrease from fifty-one to forty-two by 2027.

Given these realities, the Navy’s best option is to increase the number of ships and submarines homeported in Japan and Guam. The U.S. Navy currently maintains three cruisers and eight destroyers stationed in Japan. Deploying additional destroyers there from the West Coast would provide increased deterrence and ease the operational demand on the current Seventh Fleet ships.

Similarly, we should forward-deploy more attack submarines. (The Seventh Fleet currently has four of them.) This will be increasingly important as our attack submarine force shrinks drastically over the next eight years. Otherwise, the response time needed to bring our submarine force to bear on Chinese and Russian maritime threats will become wholly unworkable.

Increasing the number of forward-based ships is not without drawbacks. The Navy will have to boost its investments in overseas naval base infrastructure. It may also require negotiating new or updated agreements with the host nation. But these obstacles can be overcome with support from Congress and the Department of Defense.

That support should be forthcoming. Forward-basing additional ships and submarines is the only practical way to give our nation the capacity and capability needed to deter or respond to increasing Chinese and Russian threats in the Indo-Pacific region.