People tend to think of the military in terms of defending against or otherwise dealing with external threats. But there is also domestic a role for the military to play under certain circumstances.

In Washington state, the military can be tasked with working with civilian authorities in response to a range of potential disasters, from an earthquake and resulting tsunami to a terrorist attack. In the event of such a catastrophe, military assets will help to “re-establish life as you know it,” said Brig. Gen. Paul Gruver, director of the Joint Staff, Joint Force Headquarters, of the Washington National Guard at Camp Murray. He assumed his current position in March 2011.

With U.S. involvement in wars in Iraq and Afghanistan winding down, Gruver said the military can focus more on planning for — and, if necessary — responding to domestic operations in terms of natural disasters.

Lessons were learned when Hurricane Katrina, a Category 4 storm, slammed into the Gulf Coast in late August 2005, necessitating a broad response from government at all levels, including the deployment of troops. The mishmash of volunteers, government officials from various agencies and military forces led to confusion in the chain of command.

Federal agencies said they were there to support the state and local government agencies. The national guard claimed the same. Essentially, there was no central command post.

“We learned what to do and what not to do,” Gruver told the audience at Cottesmore of Life Care as part of the Gig Harbor Chamber of Commerce’s weekly public affairs forum on Thursday.

Gruver’s presentation focused on a major earthquake — at least magnitude 9.0 — striking off the coast of Washington and resulting in a massive tsunami that could have devastating consequences.

“I like to call it being shaken back to the 19th century,” he said of such a temblor that is forecast to create a 20- to 80-foot tsunami with only 15 to 30 minutes’ notice before it makes landfall.

If such an event were to take place, the death toll could be nearly 1,100 people with more than 23,600 injuries, Gruver said.

It’s impact would be far-reaching, including severe damage to the ports of Seattle and Tacoma; extensive damage and loss of life in coastal communities; extreme impacts on roads and transportation, with most bridges rendered impassable, meaning many communities would be isolated; Internet, natural gas, gas and telephone service would be mostly inoperative; and a shortage of critical life-safety resources available.

“All of the stuff we depend on will be gone,” Gruver said.

Eastern Washington would then provide support to the western portion of the state by processing incoming personnel and equipment from other National Guard units, Gruver said.

He referenced the 2004 Indian Ocean earthquake that killed more than 230,000 people in 14 countries and said it had a lag time of up to several hours between the earthquake and the impact of the tsunami.

“But this tsunami, we’ll have minutes,” he said. “So, this is a threat that’s huge and close.”

Gruver stressed self-reliance.

“You are going to help you first,” he said, adding families and businesses must be prepared to survive for a few days or longer before help arrives. “The Guard will show up, and we’ll bring a lot of our friends.”

Help would first arrive in the form of local National Guard and federal forces. In a few more days, regional National Guard forces would show up, as would military partners from Canada. In 96 hours and beyond, U.S. military personnel and resources would be on the scene.

A large federal response, including the deployment of thousands of troops can sometimes muddle the differences between the National Guard and active-duty military personnel and cause confusion on the ground. Although both wear the same uniforms and operate the same equipment, there are practical and legal differences between the two, Gruver said.

In responding to a major earthquake and tsunami, the Washington National Guard would operate under a dual-status command, meaning the Department of Defense could grant a request from the governor to command both federal and state National Guard forces, if necessary.

The dual-status commander concept represents a dramatic shift from past practices that dictated two distinct chains of command for forces that respond to domestic disasters. Federal troops who operated under “Title 10” authority reported to one commander, and National Guard members who served under “Title 32,” or state active duty authority, to another.

The dual-status command construct allows maximum flexibility in terms of the response of the National Guard, Gruver said, while it maintains state sovereignty that is at the heart of the nation’s federalist system of government.

Such a command structure also helps to minimize any chances of active-duty military personnel acting in a law enforcement capacity, in violation of the Posse Comitatus Act, the longstanding federal statute that restricts the government’s ability to use the U.S. military as a police force.

Gruver was confident that, should such a major disaster hit Washington state, the forces under his command would be up to the task.

“This is our main effort for the Guard,” he said.