Jade Helm 15 will be one of the biggest peacetime military exercises in six decades. Starting on July 15 and lasting two months, thousands of army Rangers, Green Berets, navy SEALS and other special operations forces will simulate war missions in mainly remote areas of Arizona, Florida, Louisiana, Mississippi, New Mexico, Texas and Utah. Jade Helm 15 will take place on tracts of both public and private land in the seven states. "In every case, extensive co-ordination has been completed with whoever's responsible for that land," Colonel Warren said. "In the case of private land, we've spoken and made detailed co-ordination with the patriotic Americans who have volunteered their land for the use of this important training." The Texas State Guard said on Monday it would follow Mr Abbott's order. Asked whether it felt compelled to mobilise troops in order to monitor the exercises, Lieutenant-Colonel Joanne MacGregor, the unit's public affairs officer, responded: "The Texas State Guard stands ready to support the governor of Texas when called upon to serve." Leaders of the Texas State Guard "are in the process of examining the best way to meet the governor's intent", Colonel MacGregor said. She said they are working with the US Special Operations Command "in order to alleviate any possible public concerns".

At the Pentagon, Colonel Warren said: "This is training that we've co-ordinated in great detail with both state and local officials in the various states that we'll be conducting it." Mr Abbott's order infuriated some fellow Republicans. Former state representative Todd Smith, a GOP lawyer from Euless, Texas who served in the state legislature for 16 years, posted online on Saturday what he termed an "open letter" to Mr Abbott. "As one of the remaining Republicans who actually believes in making decisions based on facts and evidence – you used to be a judge? – I am appalled that you would give credence to the nonsense mouthed by those who instead make decisions based on internet or radio – or shock-jock-driven hysteria," Mr Smith wrote. "Is there ANYBODY who is going to stand up to this radical nonsense that is a cancer on our State and Party?" "The first thing the governor should have done when he heard about concerns with US military training is to support our troops and reassure the public that our US military poses absolutely no threat to Texans," said Manny Garcia, executive director of the Texas Democratic Party. "Instead, he gave credence to conspiracy theorists by ordering the Texas State Guard to monitor US military operations." Mr Abbott, however, on Monday defended his decision.

"We are playing a pivotal role of government and that is to provide information to people who have questions," Mr Abbott told reporters after a prayer breakfast in North Austin, according to the Texas Tribune, a non-profit media organisation based in Austin. The Texas State Guard, established in 1871, has 1900 members. Unlike the Texas National Guard, it cannot operate outside Texas and cannot be pressed into national service by the president. Mr Abbott's order set off a social media firestorm between his defenders and those who mocked him. Several people tweeted to say that the Pentagon, with some two dozen US military bases in Texas – including Fort Hood, the nation's second-largest, with 45,000 soldiers – wouldn't need to send in special operations commandos if it wanted to take over the state. Senator Ted Cruz, a Texas Republican who is standing for president, said Texans were right to be worried.

"You know, I understand the concern that's been raised by a lot of citizens about Jade Helm," Senator Cruz told Bloomberg on Saturday during the South Carolina Republican Party's annual convention. "It's a question I'm getting a lot. And I think part of the reason is, we have seen for six years a federal government disrespecting the liberty of the citizens, and that produces fear. When you see a federal government that is attacking our free speech rights, our religious liberty rights, our second amendment rights, that produces distrust as to government." Not all Texans have reacted with hostility to Jade Helm 15. After the army made presentations to the Big Spring City Council and the Howard County Commission, two local agencies in West Texas, the Big Spring City Council passed a resolution granting the army permission to train within its city limits. The Pentagon has been criticised in the past for having failed to give advance notice to residents of areas that hosted training exercises. People in a Houston neighbourhood were terrified in 2013 when special operations troops swooped into a local school as a part of an exercise. TNS