The monsoon rains have finally arrived in northeast Thailand, promising to transform the parched terrain into gleaming emerald. But the downpours have done little to extinguish the incendiary atmosphere, with locals incandescent that the military — which has instigated the 12th military coup since 1932 — has yet again removed a government they cherish.

Thursday’s putsch by General Prayuth Chan-ocha has been condemned by the international community, human-rights groups and academics. Hundreds have taken to the streets in Bangkok to demand a return to civilian government, brandishing banners and hurling insults at troops. Yet few are as enraged as the people of Isaan, whose votes were largely responsible for getting the Pheu Thai party of ousted Prime Minister Yingluck Shinawatra into office.

Isaan is Thailand’s largest region, home to almost a third of the population. The majority of its inhabitants are Lao in origin, speak a dialect of Lao and are sometimes referred to as the Thai Lao. This is the ethnically and linguistically distinct home of the Red Shirt movement — backers of Yingluck’s brother, the exiled former Thai Prime Minister Thaksin Shinawatra. His implementation of populist polices such as universal health care, micro-finance and fuel subsidies earned him steadfast adoration here.

“I’d be blind if it wasn’t for Thaksin,” says Nuploy Chumphon, as she intricately weaves traditional bamboo baskets for sticky rice in Sam Phrao — a self-declared “Red Shirt village” outside the city of Udon Thani. Cataracts in each eye cost a total of just 60 baht ($2) to remedy under the local health system, says the 62-year-old, who left school at age 10 to work in the rice fields. “I want Thaksin to come home.”

Thaksin was ousted in a military coup in 2006 and convicted of corruption in absentia, charges he insists are politically motivated. The Red Shirt movement was spawned from that perceived injustice and others that followed. Thaksin-backed parties have won all five elections since 2001 by large majorities, and all but one have been ousted — twice by the military and three times by the courts.

The latest overthrow took place at 4:32 p.m. on May 22. According to local media, after a few hours of heated negotiations, General Prayuth asked Justice Minister Chaikasem Nitisiri whether his interim government was prepared to resign. Upon being told, “As of this minute, the government will not resign,” Prayuth reportedly replied, “Then, as of this minute, I have decided to seize power.” For a few seconds, some of those present thought the 60-year-old was jesting. He was not.

Long wary of such interventions, a hard core of Red Shirts has taken up arms. “When the Red Shirts have mobilized, the protests will intensify,” says Charles Keyes, professor emeritus at the University of Washington and author of a recent book on Thailand’s northeast. “If the army uses force to suppress these, there will be some hotheads among the Red Shirts who will also resort to violence.”

Whether or not the conflict develops into a civil war, he says, “will depend on the actions taken by the military.” Prayuth’s moves have, for the time being, left the Red Shirt movement rudderless. As soon as the coup was announced, Red Shirt leaders taking part in negotiations with the opposition and the military were detained and troops seized others from their homes or the street. “People from the villages call and ask why we haven’t done anything and whether we’ve given up already,” says Goravee Sala, the 28-year-old son of detained Red Shirt activist and famed radio personality Kwanchai Praipana. “But we have no leaders so we just have to wait and watch.” Some anti-Thaksin figures have been detained too. Antigovernment protest leader Suthep Thaugsuban, who is aligned with the Yellow Shirts, was among them, but he was released early Monday.

Goravee denies that the movement has any weapons, but raids in the nearby city of Khon Kaen on Friday revealed a stash of explosives, bombmaking equipment and ammunition along with assorted Red Shirt paraphernalia. Whispers abound of militants who have evaded military raids and slipped across the border to Cambodia to regroup.

Now is very much the calm before the storm, with the coming battle drawn up along all too familiar lines — old elitism vs. new pluralism. The military, judiciary and political establishment are all aligned and underwritten by the powerful royal family. They refuse to be marginalized by the upstart Thaksin, a former policeman who rose to become a billionaire telecom mogul. Many of Thaksin’s opponents even accuse him of trying to replace revered King Bhumibol Adulyadej. To them, Thaksin’s a corrupt businessman, a shameless buyer of gullible rural votes and a dangerous demagogue.

And yet many voters in the northeast refuse to be patronized. “I might be poor, I might be uneducated, but I know good government,” says one shopkeeper, hawking cartons of chocolate milk, plastic trinkets for kids and the ubiquitous Thai fish sauce. “Maybe Thaksin was corrupt, but he helped the poor people. The Democrat Party only helped themselves.”

On Sunday, yet more people, mainly political commentators, activists and journalists, were ordered to give themselves up to the military or face two years imprisonment. (One of these, the respected scholar Pavin Chachavalpongpun, said on Facebook he was too busy but offered to send his pet Chihuahua instead.) Prayuth then dissolved the Senate, bringing this coup into line with other previous military interventions.

Soldiers have set up roadblocks and are now routinely hauling people out of restaurants and houses. Red Shirt leaders, even mere village heads, are extremely wary of disclosing their location. Anyone with even the most tenuous Red Shirt affiliations is looking over his shoulder. On Sunday, the junta toughened Thailand’s already draconian lèse-majesté and national-security laws, while Prayuth appeared on television early Monday to announce that his appointment as de facto Prime Minister had been approved by the monarchy. The nation is now in lockdown, but it appears to be only a matter of time before the resistance begins.

“I will fight and if I die, then my sons will fight,” says Nuploy. The Red Shirt movement was born in a coup, and it is determined not to die in one.

Write to Charlie Campbell at charlie.campbell@time.com.