Operation Aung Zeya: How the junta broke through in Karen State

Myanmar’s military recaptured Thin Gan Nyi Naung village on September 5 after a 503-day battle with the Karen National Union (KNU) and allied forces along the strategic Kawkareik-Myawaddy Asia Highway in Karen State.The offensive—codenamed Operation Aung Zeya—involved five junta columns and marked the end of the KNU’s long-held control over a key stretch of the highway linking Myawaddy to central Myanmar. Experts note it is unusual that the junta needed more than a year and a half to mount an offensive so close to its territory, and say the sudden recapture of Thin Gan Nyi Naung after such a prolonged campaign raises questions about what enabled the breakthrough. Thin Gan Nyi Naung is a key stronghold on the Kawkareik-Myawaddy road, housing the junta’s tactical base and several battalions at the edge of the Dawna Range, where routes include the Asia Highway, an older mountain road, and forest trails. KNU Brigade 6 and allied forces began attacking the battalions on March 7, 2024, and by April 5 had forced the surrender of 617 soldiers and family members at the junta’s tactical base, bringing the entire Thin Gan Nyi Naung military region under KNU control. After losing the bases, the junta launched Operation Aung Zeya on April 7, 2024, to retake Thin Gan Nyi Naung. The allied resistance forces that had successfully captured the Thin Gan Nyi Naung area continued their offensive toward Myawaddy, where only one battalion remained. On April 15, 2024, allied resistance forces captured Infantry Battalion 275 in Myawaddy and advanced on junta positions at Bridge 2, as the junta-aligned Karen BGF remained on the sidelines. After intense firefights throughout April 20, the allied resistance forces withdrew the next morning, causing the battle to suddenly cease. On that day, the junta regained control of Infantry Battalion 275 with BGF assistance and restored the town's administrative system. But BGF members continued to handle town security. That same day, as junta columns advanced from Kawkareik toward Myawaddy, allied forces, including the KNLA, KNDO, PDF under the NUG, and the Mon Liberation Army, pulled back to block their advance. The KNU leadership later honored the fighters in a September 7, 2025, statement. One year to fall The fact that the junta’s Aung Zeya columns took a year and a half to advance along a route that should only take about an hour is also unusual. But there are a variety of factors that play into this. Resistance forces held layered defenses on the Dawna Mountains and struck junta columns from the rear, including attacks on MOC-21 in Kawkareik Township, sources close to the fighters said. Allied forces seized control of the Kyondoe–Kawkareik road on April 7, 2025, but were pushed back by July after fierce junta counterattacks. Among those fighting on the junta’s side was Bo Bi, a breakaway DKBA commander, and his loyal followers. Colonel Bo Bi, who still uses the DKBA insignia and draws support from Buddhist Karen nationalists, backed junta forces in retaking the Kyondoe–Kawkareik road. After reopening the route on July 24 and reinforcing it, the junta cleared the rear for its junta Aung Zeya columns to push forward from Kawkareik. Karen National Union (KNU) and resistance forces enter the Thin Gan Nyi Naung strategic area in April, 2024 (Photo: METRO) A strategic defeat The junta’s recapture of Thin Gan Nyi Naung on September 5 came as a sudden turn in the long battle for control of the Asia Highway. Backed by five columns and an estimated 2,000 troops, the military seized the entire area by early afternoon. The assault pushed in from multiple directions—one column from the old Dawna crossing, three from near Taw Naw Waterfall, and another from Myawaddy. Resistance fighters managed to stall advances on the Asia Highway and the old mountain road, but other columns, including one led by breakaway DKBA commander Colonel Bo Bi, reached the outskirts of Thin Gan Nyi Naung by September 4. Facing encirclement, resistance forces withdrew. A senior KNU official said the junta’s success owed much to support from Bo Bi’s faction and the Karen BGF, which tipped the balance in the junta’s favor. "The column advancing along the Asia Highway couldn't make progress and was repeatedly repelled,” the KNU source told Myanmar Now. “They were also held back in this battle. But Bo Bi’s group, with Karen guides showing the way, knew the terrain well and could march from lower villages.” Analysts say the junta’s advance, like its 1995 capture of Manerplaw, relied on local Karen groups familiar with the terrain. Unlike Bo Bi’s group, the BGF did not actively fight for the junta. But by stepping aside from the path of the advancing junta columns, they significantly helped the military. Sources close to the resistance forces said there was even support in the form of weapons and ammunition supplies to KNU and other resistance forces, as well as deploying some drone units to provide military assistance. While resistance forces faced the junta's offensive on the western side of Thin Gan Nyi Naung, the BGF positioned checkpoints between Thin Gan Nyi Naung and Myawaddy, blocking both sides. When junta columns advanced from Myawaddy in early September, BGF units pulled back, leaving Thin Gan Nyi Naung exposed, sources told Myanmar Now."Tin Win’s troops from sub-township 3 and Saw Chit Thu's troops withdrew,” said a resistance source with direct knowledge of the offensive. “To put it simply, our forces also trusted them to provide protection from that direction and left it to them. That's where the coordination broke down. When we really needed military support and called for them, the BGF didn't come.” Sources close to the resistance said BGF’s withdrawal at a critical moment drew sharp criticism from fighters, with some voicing their anger on social media. "Our comrades were upset not because we had to retreat due to overwhelming enemy forces,” the same source said. “This was between Karen organisations, and we felt betrayed. Not once or twice, but repeatedly. In this battle, it was like being stabbed in the back with a sword.” View of the Asia Highway after allied resistance forces captured Thin Gan Nyi Naung and closed the route. (Photo: METRO) Aligned with the junta Although the Karen BGF and KNU avoid direct clashes as fellow Karen armed groups, they remain divided over the junta’s planned elections, set to begin in December. The first phase will cover 102 townships, including Hpa-an, Than Daung Gyi, and Myawaddy. The KNU, which has fought the junta for more than 70 years, rejected the polls in an August 26 statement.Two days later, the junta branded the group a terrorist organisation. And then on September 5, the BGF in Myawaddy, long notorious for its role in online scams, announced it would back the elections and withdrew troops stationed between Thin Gan Nyi Naung and Myawaddy. The same senior KNU officer told Myanmar Now that BGF has no political stance and does not want to afford economic losses. "To put it plainly, it's about business interests,” the source said. “They're afraid their business interests will be damaged and destroyed, so they're quietly going along with the junta.” He added that allied groups were beginning to question whether to remain with the resistance or side with the junta, noting that while the BGF had once fought alongside them, its defection left the resistance unable to hold the ground alone. He continued that KNU's policy of continuing to fight the junta will not change just because they lost Thin Gan Nyi Naung.A Myanmar military analyst, who also requested anonymity due to fear of reprisals facing him and his family, explained that both the junta and KNU are vying for the Karen BGF’s support, pointing out that the group had previously fought alongside the resistance’s well-known Cobra columns. "The BGF played a decisive role in last year's Myawaddy battle,” the analyst said. “Their forces aren't small either. The surrender of the junta’s Thin Gan Nyi Naung tactical base wasn't solely Cobra's victory. It was also because BGF assisted the Cobra. Now, BGF cannot be blamed.” Other analysts say the junta has touted Operation Aung Zeya as a decisive victory, claiming hundreds of clashes, dozens of captured weapons, and control of key towns along the Asia Highway, though it made no mention of its own losses. Since then, the military has expanded its hold north and south of the Kawkareik–Myawaddy road and carried out fresh airstrikes near Myawaddy.While Operation Aung Zeya delivered the junta a symbolic victory, the loss of Thin Gan Nyi Naung is unlikely to end the fighting. Instead, it sets the stage for another cycle of shifting alliances and renewed battles along the Asia Highway. A group of junta soldiers are photographed after recapturing Thin Gan Nyi Naun. (Photo: Saw Ba Maung Telegram)

Operation Aung Zeya: How the junta broke through in Karen State

After 18 months of stalled advances, Myanmar’s military seized Thin Gan Nyi Naung with support from breakaway Karen forces, exposing rifts within resistance ranks and shifting the fight for the Asia Highway

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