NEW YORK — The United Nations Secretary-General Antonio Guterres has expressed his deep concern over the escalating conflict in Myanmar.

According to the UN, the number of people displaced by the fighting has reached two million, and the secretary-general appealed to all sides to protect non-combatants and open access for humanitarian aid.

The striking success of an alliance of three ethnic armed groups in Shan State in driving the army and police out of large areas along the border with China has emboldened other opposition forces around Myanmar.

In Kayah State, south of Shan State along the border with Thailand, ethnic Karenni insurgents, who already control much of the state, are attacking the main town of Loikaw and have already captured the university on its outskirts.

Volunteer People's Defence Forces (PDFs) — the militias formed by local activists after the suppression of peaceful protest back in 2021 — have launched their own attacks to take advantage of the military's setbacks in Shan State and keep up the pressure on the ruling junta.

PDFs are less experienced and more poorly armed than the established ethnic armies, but their capabilities are improving, and they often ally themselves with the more experienced ethnic soldiers, who have been fighting the central government for decades.

In Sagaing, where PDFs in the villages have been waging a desperate struggle against the military, they have recently taken the town of Kawlin, and are attacking the strategically important town of Tigyaing on the Irrawaddy River. PDFs are very active around Myanmar's second-largest city of Mandalay.

The junta has also lost control of much of the border with India. Ethnic Chin insurgents dominate their own state, and recently captured the border town of Rikhawdar.

Further south, the Arakan Army, one of the best-armed of the ethnic insurgent groups, has ended its ceasefire and begun attacking army and police posts there.

Another large ethnic force, the Karen National Union in south-eastern Myanmar, is also stepping up operations against military positions along the vital trade route to the Thai border. There are now even regular attacks on the army in Tanintharyi, the southernmost state.

All these armed groups are outgunned by a military equipped with Russian and Chinese-made aircraft, helicopters and heavy weapons, like multiple rocket launchers. But the greatly-expanded scale of the armed resistance has left Myanmar's military rulers badly over-stretched.

The air force, for example, has around 40 transport helicopters, but not all are in service. There is not the capacity to move troops around the country to concentrate them in the latest trouble spot.

And the army is reported to be suffering from low morale and recruitment difficulties. In recent battles entire units have chosen to surrender, or flee, reports of which may trickle back through the ranks.

The failure of the armed forces to mount any kind of counter-attack in Shan State after three weeks suggests either a lack of capacity — the army just cannot get sufficient forces together to try to retake the areas it has lost — or an insufficient grasp in the capital Nay Pyi Taw of how serious a challenge the military now faces.

No-one believes the military regime which seized power nearly three years ago is likely to collapse. There are still hardened combats units — the notorious Light Infantry Divisions, so often accused of atrocities — which could be deployed to much greater effect, though these are believed to be significantly depleted since the coup.

But if the opposition can keep up the pressure, and keep improving its co-ordination, elements within the junta may conclude that they need to start negotiating with their opponents. This is something the coup-leader Min Ang Hlaing has so far refused to consider. — BBC