(CNN) Military leaders, Congress and government watchdogs have all warned for years that the military faces a possible readiness crisis as it has slashed training and maintenance to keep up with budget cuts and increased operations around the globe.

Monday's collision between USS John S. McCain and a tanker off the coast of Singapore — where one sailor was found dead and another nine are missing and presumed dead — has sparked a new round of questions about the Navy's readiness and training, as it's the fourth major collision for the Navy in the Pacific this year.

But the warnings about the military's readiness problems are nothing new, and the Navy isn't alone in seeing a spike in major non-combat incidents and fatalities.

"I think it's probably approaching a readiness crisis," Rep. Adam Kinzinger, an Illinois Republican and Air Force veteran. "You have, in many cases, a Navy that is highly operational and may not get the time or the chance to train as deeply or as much as they want. You have old equipment. You have failing equipment because it's not being repaired or invested in. These are all concerns when it comes to this."

After the McCain collision, the Navy ordered a one-day operational pause across the entire fleet in order to examine the root causes of the accidents. The commander of the Navy's 7th Fleet, which operates in the Pacific, was dismissed in the fallout

The issues extend beyond Navy ships. The Marine Corps also issued a one-day grounding for all of its aircraft earlier this month following two deadly crashes. The Navy has said more than half of its aircraft cannot fly, while the Air Force is short more than 1,500 pilots. And all the military services expressed concerns about training and maintenance in the past year following a spate of aircraft training accidents

"The competitive advantage that the United States military has long enjoyed is eroding," Chairman of the Joint Chiefs Gen. Joe Dunford warned at a June Senate armed services hearing.

'A broken record'

The readiness problems stem from a variety of issues, including 16 years of the wars in Iraq and Afghanistan, conflicts that have stretched service members across the globe and the 2011 Budget Control Act constraining the military budget.

The budget caps have been a constant alarm bell. In order to deal with the budget constraints, the military has cut or deferred training and maintenance so it's deployed forces stay ready.

It's an unsustainable path, military leaders have warned.

"Our testimony today may seem like a broken record," Vice Chief of Naval Operations Adm. William Moran said at a February House armed services committee hearing. "Our Navy faces increased demand without the size and resources required to properly maintain and train for our future. And every year we've had to make tough choices often choosing to sacrifice long-term readiness to make sure we be ready to answer the call today."

At the same hearing, Air Force Vice Chief of Staff Gen. Stephen Wilson said the Air Force was "out of balance."

"This nonstop combat, paired with the budget instability and lower than planned top lines has been the United States Air Force, the smallest, oldest equipment and least ready in our history," Wilson said. "We've attempted to balance risk across force to maintain readiness. And we've forced to make unacceptable trades between readiness for structure and modernization."

Ships based overseas

While the cause of the USS McCain collision has not been determined, there were warnings that destroyers including the McCain and the USS Fitzgerald — which collided with a container ship off the coast of Japan in June — were more at risk.

A 2015 Government Accountability Office report raised concerns about ships that were stationed at ports overseas, in order to be more quickly and effectively deployed.

The report found incidents of degraded or out-of-service equipment on ships ported overseas had doubled over the past five years. The GAO concluded that the "high pace of operations the Navy uses for overseas-homeported ships limits dedicated training and maintenance periods, which has resulted in difficulty keeping crews fully trained and ships maintained."

The report specifically singled out Japan-based cruisers and destroyers, noting that those ships spend 67% of their time deployed, 33% in maintenance and did not have a dedicated training period — compared to US-based cruisers and destroyers that spent 60% of their time in dedicated training and maintenance periods.

"That creates sort of a backdrop of where the risk of problems just increases," Rep. Joe Courtney of Connecticut, the top Democrat on the armed services seapower subcommittee, told CNN.

Budget crunch hits readiness

Lawmakers in both parties have been warning that cuts to training and maintenance have harmed readiness.

The House armed services committee has already scheduled a hearing next month on Navy readiness and the "underlying problems associated with the USS Fitzgerald and USS John S. McCain."

"We ask a lot of our men and women in the Navy. The time they spend at sea is increasing, while their ships age and their funding gets cut. These are just the conditions that can lead to an increase in the kinds of accidents we are witnessing," armed services chairman Mac Thornberry said in a statement.

While Congress has been at the heart of the budget problems for the military — the Pentagon has been repeatedly caught in the middle of bigger political fights over taxes and spending — both Republicans and Democrats want to give the military more money to bolster readiness as well as buy new military equipment.

"We can keep disciplining some of these bad officers, we can go and change our training manuals, our operational manuals about how to avoid these types of situations, but at the end of the day we need to have a military that is fed, trained and ready to go, and we're not doing that right now," said Arizona Democratic Rep. Ruben Gallego, a Marine veteran. "Everyone is trying to live off this magic dollar that somehow gets stretched, and it's just not happening anymore."

In the case of the Navy's fleet, the House has pushed to build more ships than even the Trump administration requested. Navy statistics show that over the past two decades, the number of deployed ships has remained constant at around 100, while the size of the fleet has decreased from more than 450 ships in 1993 to 276 ships in 2016.

At the same time, the average length of ship deployment has increased from 167 days in 1993 to 207 days last year.

"Because shipbuilding is such a long game, we're really actually still paying the price for (building) four ships a year that was what was going on in the early 2000s and created this trough in terms of surface ships, submarines all the support vessels that we're scrambling to try to catch up with," Courtney said.