The California Guard recently welcomed a contingent of Ukrainian troops as part of a bilateral advise-and-assist rotation -- and may send more of its own soldiers to Europe next year, an official said.

Members of Ukraine's armed forces recently visited California National Guard facilities to learn more about Western ways of war amid the ongoing battle in the eastern part of the country between Russian-backed separatists and Ukrainian soldiers.

Lt. Gen. Yuriy Allerov, commander of the National Guard of Ukraine, and his staff members in November toured Camp Roberts, a major training base in central California that simulates just the kind of urban training environment the Ukrainian forces are accustomed to fighting in.

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Army Lt. Col. Jon Siepmann, director of strategic plans and policy for the California Military Department, said members of his counterpart service in Ukraine visit the state about five times a year, while California Guardsmen make eight times as many trips to Ukraine each year -- a level that may increase in 2017.

"Maybe more," Siepmann said of the level of planned rotations during a recent telephone interview with Military.com.

Similar Responsibilities

Ukraine's force is "a lot like our Guard in which it has both military responsibilities and emergency response," he said.

How a Trump administration may steer the dialogue on Ukraine -- and thus the U.S. military partnership -- remains uncertain.

U.S. and Ukrainian officials -- from Sens. Dick Durbin, a Democrat from Illinois, and Rob Portman, a Republican from Ohio, to Ivanna Klympush-Tsintsadze, a vice prime minister of Ukraine -- have raised concerns the ongoing war for Ukraine's eastern front could be neglected under a Trump administration.

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Furthermore, Trump has criticized the U.S. for acting as the backbone to the NATO alliance -- in part by supporting Ukraine's push to withstand Russian aggression -- and left the door open on whether he would defend countries he deemed as not properly contributing to the bloc's collective defense. Last summer, Trump questioned the automatic defense of NATO states and suggested the U.S. would provide aid only if they "have fulfilled their obligations to us."

So far, the U.S.-Ukraine dialogue remains ongoing, military officials said.

In addition to discussing situational awareness and command and control aspects of operations, the recent visit by the Ukrainian delegation also included casualty evacuation and airlift, according to Siepmann.

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"Their goal is to be NATO-interoperable by 2020," he said.

The crux to achieving that goal will be to establish a non-commissioned officer-like corps, similar to that of the U.S., Siepmann said. U.S. leadership is assisting Ukrainian forces in developing an NCO academy and basic leader course, he said.

"It's, of course, the backbone of our own military," he said, "and it's something that they just don't have, so we stress how important the NCO corps is."

Future Airpower Needs

Long-term assessments still need to be made, Siepmann said, such as revitalizing Ukraine's air forces, specifically the country's fighter program.

The Ukrainian air force has roughly 200 aircraft, according to a 2015 Flightglobal study cited by military blog War is Boring. The fleet, mostly comprised of MiG-29 and Su-27 fighter jets, Su-25 Frogfoot twin-engine jet aircraft and Su-24 all-weather attack aircraft, has suffered losses from shootdowns, crashes or just sitting in mothballs for years to the point of corrosive immobility.

But now, "we talk about training systems, and how we train, so it's more of a train-the-trainer type of discussion, a systems-based discussion, like, 'How are you going about training your pilots?' But really our focus is on their military as a whole, and looking at things from a systems approach," Siepmann said.

The California Air National Guard has sent some of its pilots to speak with Ukraine's fighter contingent on lesson-learned best practices, "to the extent that's appropriate, but we do have direct engagement," Siepmann said.

A handful of Guard pilots have been to Ukraine "multiple times," he said, since the U.S. stepped up to advise the country's military units after Ukraine's annexation of Crimea and after fighting between Russian-backed separatists and Ukrainian forces began in 2014.

In 2015, Maj. Gen. David Baldwin, California National Guard adjutant general, and some of his guardsmen traveled to Kiev, Ukraine's capital, to donate helmets, masks and other gear to Ukraine's forces.

Roughly a dozen airmen with the 144th Fighter Wing out of Fresno also had a scheduled visit to the capital this past spring, at the same time hundreds of airmen from the 144th, an F-15 Eagle unit, deployed to Europe under Operation Atlantic Resolve to demonstrate the U.S.'s commitment to NATO allies.

Whether fighter jets will touch down on Ukrainian soil for exercises remains to be seen. While ground troops train and advise Ukrainian soldiers in the country's west-side training center in Yavoriv, they do so on a rotational basis.

NATO's founding agreement with Russia prevents member states from permanently stationing troops or equipment, including aircraft, in former Warsaw Pact countries or Soviet republics. However, experts such Daniel Kochis, an analyst at the conservative Heritage Foundation, argue the 1997 agreement has been misconstrued and that NATO forces are justified in pursuing additional defense postures based on Russia's aggressive military activity in the region.

Regardless, "we're not currently bringing [U.S] fighter aircraft over there, but joint engagement and exercises is something that we're looking at with Ukraine, whether it be over Ukrainian airspace or in joint exercises with other countries," Siepmann said. "There's significant interest in joint-aerial operations.

"We did quite a bit [in 2016] on the air side with both fighter aircraft and also some cyber and C-130 engagement," he said.

Drones, Electronic Warfare

In addition to showing off the combined arms simulator at Camp Roberts, which trains forces by electronically simulating a humvee environment, members of the Guard "also took them to our unmanned aerial systems training facility to learn a little bit about how we deploy … drones."

In the midst of accusations of drone hacking, Ukrainian forces are looking for ways to protect their drones and other equipment from Russian military hacks.

Siepmann said they discussed capabilities, normally based on platforms such as the RQ-11B Raven and RQ-7B Shadow unmanned aerial aircraft, which Ukrainian forces are using or learning from in the battlespace. "They're buying some of these systems … and they're also interested in purchasing some of the equipment that we use," he said.

Since the interview with Siepmann, about 72 of the U.S.-supplied Raven mini-drones have proven to be inert against Russia's advanced electronic jamming signals, rendering them useless in the sky, according to a report from Reuters. The shipment was part of the larger European Reassurance Initiative, a program designed to deliver aid and non-lethal weapons to Ukraine and whose budget is slated to surge from $789 million this year to $3.4 billion next year.

Data from analog drones can easily be intercepted by Russia's electronic warfare tactics, the report said.

It is unclear if Allerov's visit to the California Guard facilities last month addressed the concern.

Meantime, Ukrainian forces are still experimenting with devices, such as repurposed commercial drones or privately manufactured ones, in hopes some of the newer technologies may withstand jamming signals from Russian-backed separatists.

The continuous dialogue with the Eastern European counterparts has given the U.S. military a new perspective on these matters, learning "quite a bit" from the urban-warfare dynamic, Siepmann said.

"The use of drones … in the conflict as well as electronic warfare, use of mortars and other artillery systems in conjunction with drones and electronic warfare has been an area they have gained a lot of experience in," he said.

The California Guard's partnership with Ukraine through the State Partnership Program, or SPP, is just a sliver of operations ongoing with U.S. and Ukrainian forces. Training in Yavoriv, led by U.S. Army-Europe and rotational U.S. Guard forces, also incorporates British, Canadian and Lithuanian trainers as part of the ongoing Joint Multinational Training Group-Ukraine.

Members of the Oklahoma Army National Guard will spearhead efforts in two six-month rotations to Ukraine in January.

This partnership really means "utilizing those relationships and those contacts that we've built," Siepmann said, "to help us do additional work in support of Ukraine."

-- Oriana Pawlyk can be reached at oriana.pawlyk@military.com. Follow her on Twitter at @Oriana0214.