Almost two months after a South Korean warship sunk mysteriously in the Yellow Sea, officials in Seoul announced an international investigation concluded a North Korean homing torpedo was to blame.

The Obama administration stood firmly behind the South Koreans on Thursday, calling the attack “unacceptable.” White House Press Secretary Robert Gibbs said North Korea’s actions will only further isolate them from the international community. “We strongly condemn this act of aggression against the Republic of Korea and send our condolences to those families of the 46 sailors that lost their lives,” Gibbs said.  Yet the administration was cautious not provoke a military conflict.

At a Pentagon press conference Defense Secretary Robert Gates refused to characterize the incident as an act of war. He said the U.S. will consult closely with the South Koreans, but it’s up to them to determine the next move. “The key thing to remember here is that this was an attack on a South Korean ship and the South Koreans need to be in the lead in terms of proposing the way forward.”

With over 30,000 U.S. service members stationed in South Korea, Gates was pressured to address the possibility of getting involved in a conflict. “If there were a problem in Korea our main arms would be the Navy and the Air Force.” It’s well known the United States Army is stretched thin in Iraq and Afghanistan. It’s also well known that North Korea boasts the one the largest land forces in the world.

State Department spokesman P.J. Crowley told reporters Thursday there’s no interest in seeing the Korean peninsula “explode”, but he said there needs to be a meaningful response. “Clearly this was a serious provocation by North Korea and there will definitely be consequences because of what North Korea has done,” Crowley said.

Technically the Koreas are still at war and much of the tension between the two occurs around the demilitarized zone, a dividing line near where the frigate Cheonan sank in the Yellow Sea.

Immediately after the announcement yesterday the North Koreans denied any involvement in the sunken ship, saying South Korea had fabricated evidence. The North threatened and “all out war” if there is retaliation.

Already Seoul has said it will ask the United Nations Security Council to take action.

Chairman of the Joint Chiefs of Staff, Admiral Mike Mullen, said Thursday U.S. forces in the region are aware of the ship incident and the war of words, but they are not operating at a heightened state of alert.