New York: President Barack Obama on Wednesday said the US will use military force, unilaterally if needed, when its core interests demand it - when Americans are threatened or when the security of its allies is in danger.
International opinion in such circumstances matters but "America should never ask permission to protect our people, our homeland, or our way of life," he said.
"The United States will use military force, unilaterally if necessary, when our core interests demand it when our people are threatened; when our livelihood is at stake; or when the security of our allies is in danger.
"In these circumstances, we still need to ask tough questions about whether our action is proportional, effective and just. International opinion matters.
"But America should never ask permission to protect our people, our homeland, or our way of life," said the US President at the graduation ceremony of the elite Military Academy in West Point, New York.
It is America that the world looks to for help, for it is the one indispensable nation, he said.
"Here`s my bottom line: America must always lead on the world stage. If we don`t, no one else will," Obama said.
A day after he announced to pull out all the troops from Afghanistan by the end of 2016, Obama, however, reiterated in a major foreign policy speech that military intervention is not the solution to all problems.
"The military that you have joined is, and always will be, the backbone of that leadership. But US military action cannot be the only ? or even primary ? component of our leadership in every instance. Just because we have the best hammer does not mean that every problem is a nail," he said.
"Because the costs associated with military action are so high, you should expect every civilian leader ? and especially your Commander-in-Chief ? to be clear about how that awesome power should be used," he added.
On the other hand, when issues of global concern that do not pose a direct threat to the US are at stake ? when crises arise that stir conscience or push the world in a more dangerous direction ? then the threshold for military action must be higher, he asserted.
"In such circumstances, we should not go it alone. Instead, we must mobilise allies and partners to take collective action.
"We must broaden our tools to include diplomacy and development; sanctions and isolation; appeals to international law and ? if just, necessary, and effective ? multilateral military action. We must do so because collective action in these circumstances is more likely to succeed, more likely to be sustained, and less likely to lead to costly mistakes," Obama said.
According to the US President, for the foreseeable future, the most direct threat to America at home and abroad remains terrorism.
But a strategy that involves invading every country that harbours terrorist networks is naive and unsustainable, he said.
"I believe we must shift our counterterrorism strategy ? drawing on the successes and shortcomings of our experience in Iraq and Afghanistan ? to more effectively partner with countries where terrorist networks seek a foothold," he said.
Praising America`s leadership in recent years, Obama said now is the need to do more to strengthen the institutions that can anticipate and prevent them from spreading.
"For example, NATO is the strongest alliance the world has ever known. But we are now working with NATO allies to meet new missions ? within Europe, where our Eastern allies must be reassured; and also beyond Europe`s borders, where our NATO allies must pull their weight to counterterrorism, respond to failed states, and train a network of partners," he said.
Likewise, the UN provides a platform to keep the peace in states torn apart by conflict, Obama said.
"Now we need to make sure that those nations who provide peace-keepers have the training and equipment to keep the peace, so that we can prevent the type of killing we have seen in Congo and Sudan," he said.
"Global leadership requires us to see the world as it is, with all its danger and uncertainty. But American leadership also requires us to see the world as it should be ? a place where the aspirations of individual human beings matter; where hopes and not just fears govern; where the truths written into our founding documents can steer the currents of history in the direction of justice.
"And we cannot do that without you," Obama said.