Recently 70 members of the foreign policy establishment sent a letter to Congress urging it to add $100 billion a year over the next decade to the defense budget, which already totals about $600 billion, claiming the Pentagon’s four military services are not receiving enough money to carry out their missions. But if these leaders were really concerned about our security, they should have also focused on the nation’s fifth military service, the Coast Guard.

Shortsighted underfunding of the Coast Guard risks preventable disaster for this essential, but overlooked, service. In his first State of the Coast Guard address, Coast Guard Commandant Paul Zukunft warned that “aging platforms and crumbling infrastructure” prohibit the Coast Guard’s ability to protect our shores. The Coast Guard is “facing unparalleled demands” for its various missions, from search and rescue to counterterrorism to icebreaking operations. However, the current starvation budget is crippling the Coast Guard’s readiness and undermining national security.

The Coast Guard is not being given the resources it needs to meet its current missions, let alone tackle evolving 21st century threats to homeland security. For this year, the Coast Guard’s total budget is just under $10 billion. This chronic underfunding is impacting all aspects of the Coast Guard’s missions, even as the scope of its missions grows.

Today, many Coast Guard ships are literally falling apart. The average age of a Coast Guard cutter is 46 years, compared to just 22 years for Navy surface combat ships. With an ancient fleet, the Coast Guard is “conducting 21st century operations from veritable museums,” as Commandant Zukunft put it.

Not surprisingly, the aging fleet has struggled to keep enough ships on the water and out of dry dock to complete its missions. For example, the recent fire aboard the nearly 40-year-old USCGC Polar Star (our lone functional heavy icebreaker) cut short the icebreaker’s Antarctic mission. However, at just $1 billion, nearly 40 percent less than just a few years ago, there isn’t enough money in the Coast Guard’s acquisition budget to pay for repairs to vessels like the USCGC Polar Sea (our second heavy ice breaker) let alone desperately needed new ships. Shore infrastructure is in equally dismal shape, with just $40 million to put a Band-Aid on an estimated $1.4 billion worth of repairs.

Lack of ships and readiness have also hampered law enforcement efforts, with drug interdictions at sea falling by 30 percent over the past 2 years. Funding shortfalls have also led to readiness shortfalls. As aging ships spend more and more time being repaired, they have fewer days for patrolling and training on the water. Some Coast Guard personnel have not had sufficient training or experience on the water to be qualified for their job grade, impacting the overall readiness of the force.

Even as the Coast Guard’s funding shrinks, its missions are expanding. As natural disasters grow more frequent, the Coast Guard will respond to more storms like Super Storm Sandy and worse coastal flooding in low-lying areas across the country. A rapidly thawing Arctic and a corresponding influx of vessel traffic presents a whole new ocean that will require Coast Guard patrols to uphold U.S. maritime laws and U.S. Arctic sovereignty. Possible oil development in Arctic waters will also place a greater burden on an already-overstretched service. The Interior Department estimates that there is a 75 percent chance of a major spill occurring during Arctic oil development or production. The Coast Guard responded to the Deepwater Horizon spill with 7,000 service members operating 60 ships and 22 aircraft. With current funding levels, the Coast Guard does not have the vessels, resources, or personnel necessary to respond to an Arctic spill.

It is unrealistic to expect the service to continue to perform at 100 percent levels with just 70 percent of necessary funding, and yet that is exactly what Congress seems to expect. Even as lawmakers cut funding for Coast Guard ships and helicopters by $70 million, they found $1 billion in last year’s budget for a new amphibious assault ship, the LDP-17, which the Navy didn’t even ask for.

The government must begin to think of the Coast Guard as a central part of national security, not as an afterthought. One way to do this would be through a unified national defense budget that looks at all of the armed services together, regardless of their department, and allocates funding based on needed capabilities. The administration and the Congress must work together to make sure this vital service gets the funding it needs. Otherwise, they run the risk of turning the Coast Guard’s proud motto of “Semper Paratus,” “Always Prepared,” into an empty phrase.

Lawrence Korb is a senior fellow at the Center for American Progress. He has taught at the U.S. Coast Guard Academy and served as an assistant secretary of defense. Maureen Smolskis is an intern with the Center for American Progress and a recent graduate of Connecticut College. She is in the process of applying for the Coast Guard’s Officer Candidate School program