Obama Warns U.S. Must Not Rush to War

President Barack Obama mounted a defiant defense of his global leadership Wednesday, rebuking critics who see him as weak but warning that not every global threat justifies a U.S. military response.

In a major speech at the West Point military academy, Obama denied U.S. power had ebbed under his watch, after he withdrew troops from Iraq and as he does the same in Afghanistan.

He also pledged to ramp up support for Syrian rebels, vowed to stand up to Russia over Ukraine and promised to make drone strikes against terror suspects more transparent.

He vowed to hold China accountable to international "rules of the road" in the South China Sea and elsewhere.

"To say that we have an interest in pursuing peace and freedom beyond our borders is not to say that every problem has a military solution," Obama said.

"Since World War II, some of our most costly mistakes came not from our restraint, but from our willingness to rush into military adventures -- without thinking through the consequences," Obama said, in an apparent reference to the Iraq war, which he has branded a disaster.

The president's speech came with his foreign policy, which was once seen as a political asset, under assault from critics who believe he is being outmaneuvered by strongmen like Russian President Vladimir Putin and China's President Xi Jinping.

"Here's my bottom line: America must always lead on the world stage. If we don't, no one else will. The military ... is, and always will be, the backbone of that leadership."

Obama was particularly exercised by those who complain he should have deployed the U.S. military in Syria or made a more robust strategic response to Russia's annexation of Ukraine, or who complain that he has left Iraq or Afghanistan to fend for themselves.

"Tough talk often draws headlines but war rarely conforms to slogans," Obama said.

"But U.S. 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," Obama told a graduation ceremony at the college.

"And 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."

Obama said he was "haunted" by the deaths of American servicemen under his watch -- including some who attended previous commencement ceremonies he had given at West Point.

Obama also made an implicit defense of his decision to call off military strikes on Syria at the last minute last year to punish chemical weapons strikes.

Critics at home and abroad warned that the decision left dangerous questions about whether Washington would stand up to "red lines" elsewhere in the world.

He also defended his decision to leave nearly 10,000 troops in Afghanistan for a year after combat troops leave at the end of this year, and to gradually reduce the presence to a detachment of troops at the U.S. embassy in Kabul by the end of 2016, just before he leaves office.

Meanwhile, Obama also warned that the United States was ready to respond to China's "aggression" but said that Washington should lead by example by ratifying a key treaty.

Obama said that the United States should shun isolationism and that its military must be prepared for crises.

"Regional aggression that goes unchecked -- whether it's southern Ukraine, or the South China Sea, or anywhere else in the world -- will ultimately impact our allies, and could draw in our military," Obama said.

But Obama emphasized caution on any decision to use force and said: "American influence is always stronger when we lead by example."

"We can't try to resolve the problems in the South China Sea when we have refused to make sure that the Law of the Sea Convention is ratified by the United States -- despite the fact that our top military leaders say that the treaty advances our national security," Obama said, not naming China directly as he diverted from his prepared text.

"That's not leadership; that's retreat. That's not strength; that's weakness," Obama said.

Senators of the rival Republican Party have refused to ratify the treaty, saying that the U.N. convention would override U.S. sovereignty.

Tensions have been rising for months between China and its neighbors at sea, with Vietnam on Tuesday accusing Beijing of ramming and sinking one of its fishing boats in the South China Sea.

Japan and the Philippines also have tense disputes at sea with China. Japanese commentators have voiced concern that the U.S. failure to prevent Russia from annexing Ukraine's Crimea peninsula in March sent the wrong signal to China.

In another reference to policy toward Asia, Obama again cited the democratic reforms in Myanmar as a success story.

The administration upon entering office in 2009 opened a dialogue with the then military-ruled nation earlier known as Burma, whose relations have improved with the United States have improved dramatically.

"Progress there could be reversed. But if Burma succeeds, we will have gained a new partner without having fired a shot," Obama said.

Myanmar has freed political prisoners, eased censorship and welcomed foreign investors, but human rights groups have voiced alarm over violence against the mostly Muslim Rohingya minority.