While Burma's military steps up battles against Kachin rebels along the border with China, security analysts say Beijing has been quietly selling advanced weapons to another insurgent group on its border, the United Wa State Army. The Wa are the largest militia in Burma and considered the biggest narcotics dealing organization in Southeast Asia.
Burma's military airstrikes and mortar attacks on Kachin rebels in recent weeks raised international concerns about the government's peace efforts. The heavy fighting in Burma's north is the worst since a 17-year cease-fire with the Kachin Independence Army broke down in 2011.
But while China calls for military restraint in Kachin state, security analysts say Beijing has been secretly arming another rebel group, the United Wa State Army.
In a December report, IHS Jane's Intelligence Review says China last year provided the Wa with advanced weapons to build up their defenses. The transfers included surface to air missiles and, for the first time, at least 12 armored vehicles the report refers to as "tank destroyers."
Thailand-based security analyst and author of the report, Anthony Davis, said Beijing is trying to balance historic camaraderie with the Wa and its relations with Burmese authorities.
"The Chinese cannot afford to ignore the ethnic forces along their border, nor at the same time can they afford to ignore the central government," Davis said. "Is that to say that China is directly supplying that equipment? No, it's not. Clearly the supplier of that equipment is known to senior elements in the government, but that is not to say that they are directly involved in financing. They need to maintain a degree of deniability here," he said.
China's Foreign Ministry declined to comment on the IHS Jane's Intelligence Review report.
The Wa are Burma's largest rebel group, estimated at up to 30,000 full and part-time fighters. Despite its professed policy of non-interference, military analysts say China has long been the largest supplier of weapons to the Wa, albeit unofficially.
The Wa were one of several ethnic militias that formed after the 1989 breakup of the Burmese Communist Party.
Beijing directly supported the communists and maintained relations with the newly formed rebel groups.
Yale University Ph. D. candidate Josh Gordon said China has been particularly close with the Wa, who speak Chinese. The Wa are more or less a proxy of China, said Gordon.
"You'll use Chinese money, Chinese cell phones, Chinese electricity for in large part, where there is electricity in the urban areas, and have connection to the Chinese Internet," he said.
Burma signed a cease-fire with the Wa in the 1990s and allowed them to govern their own territory in northeastern Shan state. They turned it into one of Asia's largest methamphetamine production bases and are considered the region's largest drug-dealing organization.
The U.S. Drug Enforcement Agency in 2011 put most-wanted pictures of Wa leader Wei Hsueh Kang in Thailand's entertainment venues.
Despite the recent escalation in Chinese weapons transfers to the Wa, Davis said Beijing is not trying to destabilize the border area. Instead, China is sending a message to Burmese authorities not to even think about attempting in Wa territory what they are doing in Kachin state where local groups are fighting Burmese forces, he said.
"The Chinese are not stoking fires in Northern Burma. By reinforcing the Wa they are reinforcing a military deterrent. If you like, they are reinforcing peace and stability which has existed for the last 20 years in a manner that's been favorable to China."
During past decades of military rule and western sanctions, China held great sway over Burma and its natural resources. But since Burma's reform-minded President Thein Sein took office, and sanctions were suspended, China's influence is being thrown off balance.
Davis said the weapons tranfers to the Wa appear to be China responding to its political reversals.
Ye Htut, a spokesman for Burma's president, declined to comment on the report by IHS Jane's Intelligence Review.
"We don't have any information on that," he said. "But, every time the Chinese government assures us they will not interfere in our internal affairs. So we accept their assurance."
China this month sent a high-level military delegation to Burma to discuss border security issues and the fighting in Kachin state. The official New Light of Myanmar newspaper said the Chinese agreed not to interfere with Burma's internal problems.