FORT BRAGG, N.C. -- Chief of Staff of the Army Gen. Mark A. Milley said the readiness of the Total Army is his No. 1 priority.

This message was at the forefront of his talk to leaders at the U.S. Army Reserve Command Senior Leader Conference, April 25, 2016, at the Iron Mike Conference Center.

Milley said America's national strategy has to be able to deal with five challenges.

"You've heard the secretary of defense talk about them," Milley said. "Russia, China, North Korea, Iran, and counter-terrorism. Of those five challenges, we have to be able to deal with two of the four named countries simultaneously, or near simultaneously, and one of them we have to defeat and the other we have to deny. At the same time, you have to maintain your current level of effort against the counter-terrorist fight and you have to protect the homeland. That's for the U.S. military, not just the Army.

"Our piece of that is pretty significant," Milley continued. "In my heart of hearts, I think we're in pretty good shape to defend the homeland. I think we're in pretty good shape to fight terrorists. I think we have the capabilities and capacity - the size of forces - to do that."

He said what concerns him is dealing with one or more of the named countries. He said the skills and methods of engaging one or more of those countries are not the same as fighting counter-terrorism, adding, this is where military readiness is a key to success.

"You and I, as an Army, have to maintain the capability and the readiness. We have to sustain that which we have learned over 15 hard years of lessons learned," he said. But added to that equation are the other state or international players.

Milley said after the fall of the Berlin Wall, Russia turned in on itself as the previous threats prevalent during the Cold War faded. Since 2005, however, he said their external behavior and foreign policy turned to becoming an aggressive power.

Starting with cyber attacks and then moving to outright armed invasions of the sovereign nations of Georgia in 2008, the illegal seizure of Crimea, and the use of covert and overt surrogates to seize the eastern portions of Ukraine, Milley said the United States and Europe had not seen that kind of behavior in decades.

"No one has seen aggressive foreign policy by any country in Europe for 70 years where armies, or surrogate armies, have crossed the borders of sovereign, independent countries," he said. "That is a big deal. It's got everybody's attention now. Ten thousand years of recorded history tells us that aggression left unanswered leads to more aggression."

Milley said the U.S. military has increased its presence in Europe to include 40-50 exercises a year to deter any future incursions.

"You can only deter your opponent if your opponent believes that you have the will and the capability," he said. "So readiness has a deterrent value as well as a war-fighting value."

When it comes to China, Milley said they are the rising power of this century - economically and militarily. He added that history shows the two go hand-in-hand.

He said while history is "not deterministic, it is suggestive. In 18 case studies between rising powers and status quo powers, 15 ended up in armed conflict between the two powers. The other three have ended up in serious military tension.

"It is our job to be ready, to provide options to the President of the United States," he said. "We know for certain that China is a rapidly rising power and they have been for 30 years and it's likely to continue. We know that for 30 years, we've seen a massive economic shift in money and resources," noting that China continues to invest in modernizing their air force, navy, army, missile force, and cyber.

"They are getting better by the day," he said. "We also see a significant shift in international behavior with a rapid militarization of the South China Sea."

He said both Russia and China are also seeing a rise in nationalism - loyalty to their respective states - that also leads to a dominant military.

Moving to North Korea, Milley said they have the most heavily armed border in the world. Add to that, their frequent military provocations and rhetoric are causes for concern for the U.S. military.

He said if violence broke out on the Korean peninsula, the U.S. would need high levels of readiness to counter the threat.

"That's the world around us," Milley said. "But there are lots of other things. Ebola, crime and drug trade in northern Mexico, and lots of bad things happening in other parts of the world.

"But those are the mission profiles we've been given, as an Army," he continued. "Our obligation to the nation is to be ready, prepared, trained, manned, and equipped, for all four of those named countries and the ability to protect our homeland and fight counter-terrorism.

"That's the reason why priority one is readiness and the challenges in front of us are pretty significant," Milley said. "And we haven't seen this level of challenges in a long, long time."

When speaking more specifically about the capabilities of the U.S. Army Reserve and the Army National Guard, Milley said the two reserve components bring unique capabilities to the Total Force concept.

"It's an incredible story, what you guys bring to the fight," he said. "First of all, the U.S. Army, as an organization, can't get off Jump Street without the Army Reserve. You guys have got it all. We can do short-term things with the regular Army. But you can't do sustained, land combat without significant elements of the Army Reserve. It's the way the system was designed. It has stood the test of time. It's fundamental to the all-volunteer concept and it's fiscally smart. So get out there and tell the Army Reserve story and connect those dots for the (American) people."

He said that no matter which component soldiers serve - active Army, U.S. Army Reserve, or Army National Guard - it's one Army.

"On a broader scale, I want to put reality on a 'one Army' concept," he said. "It's about the nation. It's about why we fight wars and how we protect our country. At the end of the day, it is one singular Army that is mutually interdependent on each other for success."

And to be successful, all signs point back to readiness.

"I need to raise your readiness," Milley said. "I am going to consciously and willingly raise your readiness levels because they are tied directly to the rapid response to war-fights."