There could be 3,000 more Marines in uniform next year as Congress weighs boosting the size of the service — but one of the Corps' top leaders said it still might not be enough.

House lawmakers are calling for the Marine Corps to be increased to 185,000 leathernecks. But Assistant Commandant Gen. John Paxton said Monday that in order to meet all of its missions, the Corps needs at least 186,800 Marines.

That was the number of Marines the service needed in 2011, before across-the-board spending cuts known as sequestration went into effect.

"That was before Ukraine, before Syria, before South China Sea, before WikiLeaks," Paxton said at the annual Sea-Air-Space exposition held outside of Washington, D.C. "To us, 186,800 is about the floor so the number may [need to] be north of there."

Having more Marines would allow the service to retain its conventional punch while also specializing in new skill sets to meet Russia's and China's advances in cyber and electronic warfare, Paxton added.

Still, Commandant Gen. Robert Neller isn't confident he'll get 185,000 Marines, let alone get the extra 1,800 Marines his deputy is calling for. The issue is gearing up to end in a congressional showdown as the Senate's plan falls in line with the current planned end strength of 182,000 Marines in 2017.

Here's a look at what's at stake.

'The world has changed' 

All of the military services have faced steep budget cuts in recent years, but Marines' operational tempo has yet to slow.

U.S. troops have been tapped to respond to aggressive acts by Russia, the rise of the Islamic State group and a more assertive China. Those issues weren't high on many people's minds when the military personnel drawdowns kicked off.

"The world has changed," said Mark Cancian, a retired Marine officer and senior international security adviser with the Center for Strategic and International Studies. "Arguably the world is a more dangerous place than had been envisioned, and this feeds into the belief that forces at least have to stop getting smaller and actually start getting larger."

U.S. Marines with Combined Arms Company fire an M1A1 Abrams tank during a field training exercise at Novo Selo Training Area, Bulgaria, Sept. 21, 2015. The Marines underwent several days in the field to prepare for multinational training exercises over the next few months. (U.S. Marine Corps photo by Lance Cpl. Melanye E. Martinez/Released)
U.S. Marines with Combined Arms Company fire an M1A1 Abrams tank during a field training exercise at Novo Selo Training Area, Bulgaria, Sept. 21, 2015. The Marines underwent several days in the field to prepare for multinational training exercises over the next few months. (U.S. Marine Corps photo by Lance Cpl. Melanye E. Martinez/Released)

Marines with the Bulgaria-based Combined Arms Company fire an M1A1 Abrams tank during a field training exercise in Eastern Europe. The new Marine unit was stood up last year to assure allies in the region concerned about Russian aggression.

Photo Credit: Lance Cpl. Melanye Martinez/Marine Corps

In 2015, Marines carried out approximately 100 land operations, 20 amphibious missions, 140 theater security cooperation events and 160 major exercises, Neller noted in a March briefing to the Senate Armed Services Committee.

That type of operational tempo has left the force pinched in certain areas.

New threats

While Congress might expect the Marine Corps to buy back an infantry battalion or two, Cancian said it's likely the service would have other ideas.

Cyber Marines, drone operators and other high-tech specialties will be needed to meet the threats posed by countries like Russia and China, he said.

U.S. Marines with II Marine Expeditionary Force and 2nd Air Naval Gunfire Liaison Company conducts a mission on Virtual Battlespace 3, while receiving support from a Joint Terminal Attack Controller during Emerald Warrior, aboard Camp Lejeune, N.C., May 9, 2016. Simulation centers from Charleston Air Force Base, S.C., Eglin AFB, F.L., Cannon AFB, N.M. and Distributed Training Operations Center, I.A. all took part in Emerald Warrior providing various support assets vital to the JTACs mission of bringing the air element to the ground element. (U.S. Marine Corps photo by Cpl. Justin T. Updegraff/ Released)
U.S. Marines with II Marine Expeditionary Force and 2nd Air Naval Gunfire Liaison Company conducts a mission on Virtual Battlespace 3, while receiving support from a Joint Terminal Attack Controller during Emerald Warrior, aboard Camp Lejeune, N.C., May 9, 2016. Simulation centers from Charleston Air Force Base, S.C., Eglin AFB, F.L., Cannon AFB, N.M. and Distributed Training Operations Center, I.A. all took part in Emerald Warrior providing various support assets vital to the JTACs mission of bringing the air element to the ground element. (U.S. Marine Corps photo by Cpl. Justin T. Updegraff/ Released)

Marines with 2nd Air Naval Gunfire Liaison Company conduct a mission on a simulation center called Virtual Battlespace 3. As missions get more technical and complicated, the Marine Corps may need additional cyber warriors.

Photo Credit: Cpl. Justin Updegraff/Marine Corps

More Marines "would help the Corps build these new kinds of capabilities without having to cut the old capabilities," Cancian said. "... It might help them fill in some of the shortages in the current structure."

Improving readiness — especially in the aviation community — would likely be another priority. Republican members of the House Armed Services Committee sounded the alarms about a military readiness crisis earlier this month following reports that the Marine Corps is experiencing trouble with its aviation fleet.

As a result, the lawmakers proposed "increasing Marine Corps end strength by 3,000 Marines to help address shortfalls in critical skill sets and fully funding the military pay raise to help incentivize Marines to stay in the Corps," according to a release.

Curbing long deployments

About 2,300 West Coast-based Marines recently arrived in the Middle East for a nine-month deployment. Members of the 26th Marine Expeditionary Unit's Task Force Spartan also remained behind in Iraq recently as the rest of their unit returned home. They could be there until August, which would leave them deployed for about 10 months.

Dakota Wood, a retired Marine officer and senior research fellow at the Heritage Foundation, said Marines should expect to take on more work if the service's end strength remains at 182,000.

"Unless workload decreases commensurate with the size of the force, the Marines who remain in a smaller Corps have no option but to shoulder longer days and more deployments," he said.

Deployments stretching beyond the typical six months could be the new norm not only for planned missions, but also as Marines respond to unexpected crises, Wood added. Since natural disasters or other threats can pop up unexpectedly, it's nearly impossible to plan for them or predict where they'll take place, he said, which poses challenges for a force already stretched thin.

The expense 

Adding thousands more Marines comes with a price tag, and how the military will foot that bill is still up for debate.

The costs associated with any kind of plus-up would also depend on what kind of Marines would be added, said Col. William Tosick, deputy director of Manpower Policy.

Adding more junior Marines through the typical accession process is relatively simple, he said. The Marine Corps would simply recruit and train more new leathernecks.

But adding more seasoned noncommissioned officers or officers is more complex and expensive, he said. If the service needs to retain its most-experienced Marines, it might require more money for re-enlistment bonuses.

"It takes time to recruit, train, promote and assign Marines to new structures — especially with aviation and cyber-related units," Tosick said.

U.S. Marine Corps Lance Cpl. Jessica Kerr, a plane captain with Marine Tactical Electronic Warfare Squadron (VMAQ) 2, 2nd Marine Aircraft Wing conducts maintenance on a Marine Corps EA-6B Prowler assigned to VMAQ-2, prior to a flight during Exercise Northern Edge 15 at Eielson Air Force Base, Alaska, June 15, 2015. Northern Edge is Alaska’s premier joint training exercise designed to practice operations, techniques and procedures as well as enhance interoperability among the services. Thousands of participants from all services, Airmen, Soldiers, Sailors, Marines and Coast Guardsmen from active duty, Reserve and National Guard units are involved. (U.S. Marine Corps photo by Cpl. Suzanne Dickson/Released)
U.S. Marine Corps Lance Cpl. Jessica Kerr, a plane captain with Marine Tactical Electronic Warfare Squadron (VMAQ) 2, 2nd Marine Aircraft Wing conducts maintenance on a Marine Corps EA-6B Prowler assigned to VMAQ-2, prior to a flight during Exercise Northern Edge 15 at Eielson Air Force Base, Alaska, June 15, 2015. Northern Edge is Alaska’s premier joint training exercise designed to practice operations, techniques and procedures as well as enhance interoperability among the services. Thousands of participants from all services, Airmen, Soldiers, Sailors, Marines and Coast Guardsmen from active duty, Reserve and National Guard units are involved. (U.S. Marine Corps photo by Cpl. Suzanne Dickson/Released)

Lance Cpl. Jessica Kerr, a member of Marine Tactical Electronic Warfare Squadron 2, conducts maintenance on an EA-6B Prowler. Training Marines to work in fields like aviation maintenance or cyber requires an investment.

Photo Credit: Cpl. Suzanne Dickson/Marine Corps

For now, Neller said he's preparing to make do with the size of the Marine Corps as it stands today.

"The real thing is: OK, how do we transition this force?" he said Monday at the Sea-Air-Space expo. "I'm not assuming that we're going to get the funding to get any more people even though there's actions in the legislation to do that."

Senior Reporter Jeff Schogol contributed to this report.

Matthew L. Schehl covers training and education, recruiting, West Coast Marines, MARSOC, and operations in Europe, Africa and the Middle East for Marine Corps Times. He can be reached at mschehl@marinecorpstimes.com.