The Army says the size and scope of Jade Helm 15, a Special Operations exercise that begins in July, set it apart from other training exercises. Also setting it apart: The widespread conspiracy theories that the U.S. is preparing to hatch martial law. The Post's Dan Lamothe explains. (Tom LeGro/The Washington Post)

For a made-up military mission, Jade Helm 15 is impressively elaborate: The two-month simulation planned for this summer spans much of the Southwest, requiring special forces from four branches of the military to carry out covert operations amid “hostile” territory in Texas, Utah and part of California.

In at least one of those states, hostility toward the operation has begun a few months early. Online and at in-person meetings, many Texans have expressed suspicion and outright opposition to the project. Some are understandably worried about how it’ll affect their daily lives, while conspiracy theorists claim it’s an attempt to institute martial law, possibly in collusion with Wal-Mart.

In response, Texas Gov. Greg Abbott (R) has ordered the State Guard to monitor federal troops there during the exercise.

“During the training operation, it is important that Texans know their safety, constitutional rights, private property right and civil liberties will not be infringed,” Abbott wrote in a letter to Maj. Gen. Gerald Betty of the Texas State Guard Tuesday.

[As conspiracy theories persist, governor asks Texas State Guard to monitor military’s Operation Jade Helm 15]

Events for the exercise are outlined in a map among unclassified documents posted online last month. Army sources have verified to The Washington Post that the map is legitimate.

U.S. Army Special Operations Command said simulated exercises like this are routine, though they are rarely so broad in size and scope, and that the public won’t experience any disruption in their day-to-day lives, since the entire operation takes place in pre-coordinated remote areas.

But that hasn’t convinced some Texans.

At an information session in Bastrop on Monday, command spokesman Lt. Col. Mark Lastoria fielded questions about whether Jade Helm 15 will involve bringing foreign fighters from the Islamic State to Texas, whether U.S. troops will confiscate Texans’ guns and whether the Army intends to implement martial law, according to the Austin American-Statesman.

“It’s the same thing that happened in Nazi Germany: You get the people used to the troops on the street, the appearance of uniformed troops and the militarization of the police,” Bastrop resident Bob Wells told the Statesman after the meeting. “They’re gathering intelligence. That’s what they’re doing. And they’re moving logistics in place for martial law. That’s my feeling. Now, I could be wrong. I hope I am wrong. I hope I’m a ‘conspiracy theorist.'”

According to the Statesman, Lastoria attempted to assuage residents’ concerns, saying the operation in Bastrop County will take place almost entirely on private land leased to the Army by the owner. And participants won’t be trying to sneak through the population undetected — everyone involved will wear uniforms or orange armbands signaling that they are part of the exercise, he said.

[Why Operation Jade Helm 15 is freaking out the Internet — and why it shouldn’t be]

Concerns about the operation extend beyond Bastrop. Texas talk show host and self-described “thought criminal against Big Brother” Alex Jones ran a story about the operation under the headline: “Feds preparing to invade Texas, list state as ‘hostile.'”

“Texas is listed as a hostile sector. Of course we are. We’re here defending the republic,” he said on his show.

Multiple Web sites of varying repute also drew a link between the operation and a recent Wal-Mart announcement the chain will be closing five stores, two of them in Texas.

“Are the closed Walmarts being activated as central command for underground operations?” read a headline on IntelliHub, which calls itself the “Civilian Intelligence Agency.”

Other sites posted a video allegedly showing underground tunnels between the shuttered Wal-Mart locations and Jade Helm training sites.

In his letter to Betty, Abbot said his decision to have state troops monitor the exercise is intended to “address concerns of Texas citizens and ensure that Texas communities remain safe, secure and informed.”

“By monitoring the operation on a continual basis, the state guard will facilitate communications between my office and the commanders of the operation to ensure that adequate measures are in place to protect Texans.”

According to Houston ABC affiliate KTRK, Texas residents have dealt with simulated military exercises before. In 2013, a special operations exercise in which helicopters and armed men in camouflage descended on a Houston school terrified residents, who said they hadn’t been warned.

This time, the Army said it is communicating with affected communities as much as possible in advance of the operation, which begins in mid-July and runs through September.

“We understand there’s concern out there on social media; there’s a significant amount of inaccurate information, which I hope I clarified today for a lot of people,” Lastoria, the command spokesman, said at the Bastrop information session Monday, according to KXAN. “What I want them to know is: We’re going to be conducting the training exercise safely, and courteously. We’re not going to interfere with their privacy or their rights with this.”

According to Lastoria, the exercise is important to help prepare troops for the challenges of modern warfare — a goal he believed Texans would support.

“Texans are historically supportive of these efforts to prepare our troops,” he said. “People want to make this something that it is not.”