Washington (CNN) - The United States hopes cool, careful language will keep the North Korea crisis from boiling over.
The Obama administration has been vocal in condemning North Korea for sinking a South Korean navy ship in March and killing 46 South Korean sailors. It is accusing North Korea of aggression and provocation.
But you won't hear American officials call this "an act of war." In fact, from President Barack Obama on down the command chain in this latest Korean crisis, "war" is missing in action.
Obama set the tone, offering support and condolences to the South Koreans in March. Once an international investigation was completed last week, a White House statement called the ship sinking "an act of aggression ... one more instance of North Korea's unacceptable behavior and defiance of international law."
Secretary of State Hillary Clinton hit the same notes during her trip to China.
"We are working hard to avoid an escalation, belligerence and provocation," Clinton said Monday. "This is a highly precarious situation that the North Koreans have caused in the region and it is one that every country that neighbors or is in proximity to North Korea understands must be contained."
White House Press Secretary Robert Gibbs said Monday U.S. support for the defense of South Korea is "unequivocal." But he didn't mention war.
"Specifically, we endorse (South Korea's) President Lee's demand that North Korea immediately apologize and punish those responsible for the attack, and, most importantly, stop its belligerent and threatening behavior," Gibbs said in a prepared statement.
North and South Korea technically remain at war, despite the 1953 armistice and a non-aggression pact. And North Korea has a huge standing army, bristles with missiles and has a nuclear arsenal refined by two tests of nuclear devices.
State Department spokesman P.J. Crowley said Friday the sinking of the ship was a violation of the armistice but he chose the phrase "act of aggression."
"As we've made clear, this was a clear and compelling violation of the existing armistice. It was without doubt a hostile act. It was provocative. It was unwarranted. I think our characterizations are broadly consistent," Crowley said.
Over at the Pentagon, Secretary of Defense Robert Gates and the chairman of the Joint Chiefs. Adm. Mike Mullen, both sidestepped questions about whether what North Korea did constitutes an act of war.
"Well, first of all, we certainly support the findings of the South Korean investigation. We obviously are in close consultation with the Koreans," Gates said last week. "The attack was against one of their ships. ... Naturally they would have the lead in determining the path forward. They've laid out some paths forward, and we will be consulting very closely with them as we move ahead."
Mullen was equally evasive.
"Certainly we're concerned about it," he said. "We've supported them. We've helped them in the investigation and we agree with the conclusion. They're a great friend and great ally, and we'll continue to do that."
Nicholas Szechenyi, a fellow at the Center for Strategic and International Studies, said the tone is to be expected.
"If you respond to bombastic rhetoric with equally hot rhetoric, chances are this could escalate," Szechenyi said in a telephone interview with CNN.
"This is a very sensitive period," he said. "You have to be very careful in forming a response because North Korea is so unpredictable, You don't want this crisis to develop into all-out war."
At the Heritage Foundation, Senior Research Fellow Bruce Klingner said avoiding the phrase "act of war" is both a question of how legal experts may evaluate what happened according to international rules, as well as caution.
"It may be both definitional as well as concerns about inflammatory language," Klingner said.
He said the United States is taking an appropriate tact in supporting South Korea. But he pointed out that the South Koreans themselves, outraged by the ship's sinking and loss of life, are treading carefully.
"The Korean people are angry but not angry enough to bring about an all-out war on the Korean Peninsula," Klingner said.
The United States is standing with South Korea and its decision to halt trade agreements with North Korea. It also is emphasizing - in both words and deeds - its military ties to South Korea, including an announcement Monday at the Pentagon of joint U.S.-South Korean military anti-submarine exercises.
And the United States is holding its South Korean ally close.
Clinton will be in Seoul Wednesday; Gates will meet his counterpart in coming weeks; and Obama will see the South Korean leader, Lee Myung-bak, at the G-20 meeting of developed countries in Canada in June.