WASHINGTON -- The effects of delayed defense budgets, the dearth of confirmed civilian leadership in the Pentagon, modernization, Afghanistan, and great power competition were all topics the president's nominee to be the next chairman of the Joint Chiefs of Staff faced from the Senate Armed Services Committee at his confirmation hearing.If confirmed, Army Chief of Staff Gen. Mark A. Milley would be the 20th military officer to fill the role, succeeding Marine Corps Gen. Joe Dunford, whose term expires Sept. 30.The general opened last week's hearing by acknowledging to lawmakers that the international order, in place now for over 70 years, is under threat."From East Asia to the Middle East to Eastern Europe, authoritarian actors are testing the limits of the international system and seeking regional dominance while challenging international norms and undermining U.S. interests," Milley said. "Our goal should be to sustain great power peace that has existed since World War II, and deal firmly with all those who might challenge us."Also what has changed is warfare itself, Milley told the senators. New characteristics of warfare include space, cyberspace, and new technology that's not been seen before. Competing in the new environment, he said, will require great adaptation by the U.S. military.If confirmed, he said, his priorities are to "provide the best military advice, to maintain steady continuity of military leadership, implement the National Defense Strategy with emphasis on increasing the readiness and modernization of the joint force, maintain and grow our network of allies and partners, sustain great power peace in an era of great power competition and provide unwavering support, care and leadership to our troops and their Families."Of interest to many lawmakers was Milley's insight into how delayed defense funding, continuing resolutions, and even the possibility of a yearlong continuing resolution, might affect military readiness."I think the impact would be significant," he told the Senate panel. "I think a CR [would be], in the words of the National Defense Strategy commission, they said the word 'reckless.' I think a CR has a very significant negative impact on the training, equipping, readiness and modernization of the U.S. military."Without a timely defense appropriation bill, Milley said, "I think you're going to have issues with procurement, new starts, and delays of acceleration of programs that are already there. I think your research, development, science, technology, [and] the modernization we are talking about to face the challenge of China in the future or any other country in the future. All of those will be negatively impacted unless we have the full budget passed."More than just money, Milley said, lack of a timely budget sends a message to adversaries, allies, and service men and women about the importance the U.S. places on defense. "Those are also negative impacts," he said.Modernization of the joint force has been a buzzword of the Defense Department for years now, and it's been a focus of Milley's since he took the helm at the Army in August 2015. If confirmed as the top military leader in the Pentagon, Milley said, his No. 1 modernization priority for the department would be the nuclear triad.The nuclear triad: submarine-based, land-based, and air-delivered weapons -- provide deterrence that has kept war from breaking out again since World War II, Milley said. Redundancy within the triad is not an issue, he told lawmakers -- it's critical."Each leg of the triad gives you a different capability. ... All three present different problem sets to any adversary or enemy," he said. "I think it's important to keep all three."Milley also said that non-nuclear conventional weapons are no substitute for the deterrence provided by the nuclear triad.A second priority for modernization, he said, is space."It's a new domain of military operations," he said. "We've got a considerable amount of both commercial and military capability in space that need to be protected, and all the technologies that go with space. In addition to that, I would say artificial intelligence and hypersonics, and there's many, many other technologies."China is providing the impetus to modernize more quickly, Milley said. Chinese modernization is underway, and it's moving fast, he added."I think China has, for going on 30, 35 years now, embarked upon what they refer to openly in the media and their speeches as 'the China dream,'" Milley said. "That is to be at least a peer competitor, a world-class military with the U.S. military, by the mid-2030s. And they want to have the capability to defeat us by mid-century. They are moving out on that in all the domains."Meanwhile, more than a dozen key Defense Department civilian leadership roles are filled by those in an acting or "performing the duties of" capacity. That's a problem for lawmakers, and Milley confirmed it's a problem for uniformed personnel as well."I think it is very important to fill the nominated positions and get them through the system as quickly as we can, properly vetted and confirmed," Milley said. "Having a confirmed person in place, I think, clearly helps out us in uniform, and it also clearly delineates civilian control of the military -- I think it reinforces that. The civilian oversight is of critical importance, and they interface with Congress and others [in the] interagency."Since 2001, the United States has been at war in Afghanistan. Milley said the end to that war must not come until conditions are met."I think that the war in Afghanistan, at least American participation in the war in Afghanistan, comes to an end when our interests are met, and I think that will be met through a negotiated settlement with the Taliban," he said. "I think we're seeing some progress."Milley said the U.S. has goals in Afghanistan, such as ensuring that it is never again a safe haven for terrorists who might threaten the United States. Continued presence in Afghanistan by American forces is an important part of ensuring that an agreement with the Taliban can happen, Milley said, adding that "pulling out prematurely would be a strategic mistake."Milley told lawmakers he's grateful for being nominated to the position of chairman of the Joint Chiefs of Staff, and he pledged to work with Congress in the role to keep the country safe."I'd like to thank the president of the United States for the trust and confidence he has placed in me," Milley said. "If confirmed, I pledge to you and to the American people and to the president that I will always provide my best military advice to him, the secretary of defense, the National Security Council and the Congress to ensure America's global national security interests are assured."