During Tuesday night's State of the Union address, President Barack Obama had an opportunity to engage in the debate about America's role in the world. Unfortunately, he failed to do so. He speaks eloquently of America's role as a "beacon to all who seek freedom," but stood idly by as protesters took to the streets in Iran, Syria, and elsewhere, pleading for American support, only to be rebuffed. He seeks a world without nuclear weapons even as rogue regimes such as North Korea and Iran have advanced their nuclear programs on his watch. The president talks of a "pivot" to Asia, while overseeing massive defense cuts that won't leave us with naval assets to pivot with. America's free enterprise system has given us the means to protect our people and advance the goals of global liberty, prosperity, and safeguarding human rights. Unfortunately, our weak economy has not only made it difficult for people to find well-paying jobs; it has made it easier to give in to the temptation of disengaging from the world. The biggest foreign policy problem facing the United States right now is not too much U.S. engagement, but the danger of a world in which we increasingly refuse to lead. There are few global challenges that can be solved without decisive American leadership. What happens in Syria, where more than 70,000 people are dead after almost two years of fighting, is integral to our interests. The specter of chemical weapons falling into the hands of terrorists and being used against U.S. personnel in the region or against U.S. allies should move us toward action even if the humanitarian toll does not. The president spoke on Tuesday about ending the war in Afghanistan. But he failed to discuss why Afghanistan's stability is important to America and why we must ensure that this country -- in which we have invested so many American lives and so much support -- does not once again become a safe haven for terrorists who seek to attack us. Similarly, potential instability in East Asia, caused by China's rise and North Korea's ongoing provocations, will directly impact our economic security and the system of alliances we have constructed in that region. That is why this week I urged the Senate Foreign Relations Committee to hold a series of hearings examining these challenges and cosponsored legislation that calls for new sanctions and enhancements to the U.S. military posture in the region in response to North Korea's nuclear test. A crisis in East Asia or the Middle East will impact the bottom lines of many American households. It's not an exaggeration to say that what happens in faraway places such as Yemen and Mali might be felt by those living in the heartland of America -- and if not today, then very soon. That is why we must ensure that our foreign assistance programs are effective and transparent, with meaningful monitoring and evaluation to ensure that taxpayers' money is being put to good use, and that poverty and lack of opportunity do not create new breeding grounds for terror and hatred. The president's policies have often, in effect, been to just ignore many of these problems. He seems to believe that if left untouched, they will either go away or be solved by others, without consequences for the American people. Unfortunately, this misguided view is also shared by some in my own party. Our prosperity depends upon the liberal international order that America has supported since the end of World War II. In addition to such economic and security implications, indifference or inaction undermines America's standing in the world and weakens the moral underpinnings of our republic. This nation and its timeless ideals have for centuries been a beacon of hope for those seeking to transform their own societies or who have sought better lives and greater opportunity for their children by fleeing to our shores. As modern day activists struggle for their fundamental human rights, it is our duty to speak out on their behalf and, where possible, provide assistance. That is why when we fail to adequately assist the embryonic Libyan government in confronting instability in that country, ignore the plight of persecuted minorities in Egypt and elsewhere, or neglect to stand up to tyrants like Vladimir Putin in Russia, we are in danger of losing part of ourselves. Of course, the United States can't be involved in every conflict or solve every problem. But our failure to address our fiscal problems at home has unfortunately given our allies -- whether longstanding ones like Israel, or potential future partners in the Middle East and Asia -- cause to question our staying power and commitment to their security and our shared ideals. There is no question we need to get our fiscal house in order. But we cannot do so by sacrificing our national security and by forcing our men and women in uniform to bear the brunt of paying to fix a debt problem they did not cause. Congressional Republicans have proposed ways to offset the sequester, automatic budget cuts set to go into effect next month. It's time for the president to propose a way forward other than just raising taxes. Fulfilling the promise of America will only be possible if we embrace, not continue to run away from, the essential role that our country has played in contributing to global stability. This is a role that has aided our own prosperity and an important part of what makes our country exceptional. That will require assertive leadership both home and abroad. It's time to take up the challenge.