A fresh outbreak of border violence in Central Asia has raised doubts about China's plan to start building a gas pipeline through Kyrgyzstan and Tajikistan this year.
The deadly clash between border guards of the two countries on July 10 was a virtual replay of fighting in January, suggesting there has been little easing of tensions between the two neighbors in the past six months.
The latest incident in Kyrgyzstan's Batken province erupted over attempts to connect a water pipeline to Tajikistan's Vorukh enclave, an ethnic island to the south of the unsettled 970-kilometer (602-mile) bilateral border.
Although accounts vary, Interfax reported that shooting broke out when Kyrgyz guards tried to stop some 30 Tajik workers from laying the line from the Karavshin River to the enclave village of Bedak across disputed territory.
The Kyrgyz State Border Service said that guards fired warning shots after the workers threw stones, but that nearby Tajik forces then also opened fire, leading to an exchange.
The fighting killed one Tajik civilian and wounded seven others, as well as a Tajik border guard, according to the country's Ministry of Foreign Affairs.
Kyrgyzstan charged that Tajik positions attacked twice, using mortars, grenade launchers, and artillery, but Tajikistan issued a denial. "It should be noted that the Tajik border guards did not fire a single shot," a foreign ministry statement said.
Was conflict planned?
The eurasianet.org website noted that the violence took place three days after the breakdown of talks to settle the earlier conflict in January over construction of a road to bypass Vorukh.
That project led to gun and mortar fire that wounded five border guards and a policeman on the Kyrgyz side and two border guards from Tajikistan.
In the latest encounter, Kyrgyz officials cited alleged signs that the conflict was planned.
"They include the lightning-fast reaction of the Tajik government bodies to the incident, recurrent artillery attacks ... and the attempt to persuade Kyrgyzstan that [it] is impossible to control civilians," an unnamed high-ranking Kyrgyz security official told Interfax.
"All this will inevitably lead to the protraction of the process of the national border delimitation and demarcation," the official said.
On July 15, Tajik residents of the enclave attacked the car of a Kyrgyz military prosecutor sent to gather evidence for a case of attempted murder, according to Kyrgyzstan.
On Monday, the two countries agreed to joint patrols in the conflict area, the ITAR-TASS news agency reported, citing the Kyrgyz border guard service.
The two sides also agreed to avoid future outbreaks and investigate the recent incident jointly, according to the Kyrgyz service.
Pipeline at risk
The frictions are likely to raise risks for China's plan to start work this year on a project to build a major gas pipeline through the two impoverished countries.
The "Line D" project would form the fourth strand of the Central Asian Gas Pipeline (CAGP) system, which China National Petroleum Corp. (CNPC) opened in 2009 to tap resources in Turkmenistan with a route through Uzbekistan and Kazakhstan.
Uncertainty has surrounded Line D since reports of the plan for the alternate route emerged early last year.
President Xi Jinping and his Turkmen counterpart, Gurbanguly Berdymukhammedov, confirmed support for the project last September during Xi's visit to Ashgabat as the countries declared a strategic partnership and pledged a major increase in Turkmen gas supplies.
But China has said next to nothing about the risks and the reasons for choosing a new route through Kyrgyzstan and Tajikistan, the only two countries of former-Soviet Central Asia that are almost wholly dependent on imports of oil and gas.
The previous three strands of the CAGP run some 2,000 kilometers (1,242 miles) to Xinjiang from Turkmenistan through Uzbekistan and Kazakhstan, all petroleum exporters.
Analysts say the decision to bypass Kazakhstan may be driven by reports that transit gas has been diverted to ease winter shortages and the need for diversified routes.
But the risks of pursuing a new cross-border course through territories that have never been cleared may be far greater.
Ethnic conflicts between Kyrgyzstan and Tajikistan have raised further doubts.
If the two relatively cooperative neighbors come to blows over a water pipeline, what are the chances for an oil pipeline to succeed?
"In these matters, one has to rely on folk wisdom. We have lived side by side for a thousand years, and I hope we will find solutions that are positive for both sides," said Tajik Foreign Minister Sirojidin Aslov on a visit to the Kyrgyz capital Bishkek.
Since September, CNPC has said little about the project, adding to the uncertainties, although the line is scheduled to be opened in 2016.
Last month, Lv Jianlong, director of strategy planning for the pipeline system, told Interfax that CNPC is "still working out a route and other details with Beijing."
Edward Chow, senior fellow in the energy and national security program at the Center for Strategic and International Studies in Washington, said the rationale for Line D has never been clear.
"It's always had more questions than answers," Chow said.
More than needed
For one thing, China may already have more pipeline capacity from Central Asia than it needs, considering the pace of exports.
Last year, the CAGP system carried 27 billion cubic meters (953 billion cubic feet) of gas to China, mainly from Turkmenistan, supplying it with over half its gas imports, CNPC said.
With the addition of Line C, which opened in June, capacity will reach 55 billion cubic meters (bcm) per year by the end of 2015, according to Interfax. Line D would add another 25 bcm, giving the system 80 bcm of capacity by 2020, according to CNPC.
Turkmenistan has promised China that its exports would reach 65 bcm per year under a 2012 framework agreement, with 10 bcm expected from Uzbekistan and 5 bcm from Kazakhstan.
Much depends on development of Turkmenistan's giant but difficult Galknysh (Revival) gas field, but progress there has reportedly been slow. CNPC has said it does not expect more than 1 bcm from the field this year, Argus Media reported in March.
"In my mind, they have to build up the production capacity for exports in Turkmenistan, particularly from Galknysh, in order to fill lines A, B, and C," said Chow.
Galknysh is thought to be the second-largest gas deposit in the world.
But estimates of pipeline capacity and export targets have varied over the years. Timing is also uncertain for development of major resources recently discovered in Tajikistan, further clouding the need for Line D, Chow said.
Another complication would be ethnic tensions that could arise from the influx of many thousands of Chinese workers for the pipeline project if it goes ahead.
In June, violence also broke out at a refinery project in the northern Kyrgyz city of Tokmok as Chinese migrant workers rioted and held Kyrgyz employees hostage in a dispute over pay.
Police fired shots to restore order and 25 of the workers were deported, eurasia.net reported. Such tensions appear to be rising along with Chinese investment.
"As the Chinese become more visible, Kyrgyz have grown suspicious that their tiny country could be swallowed by their giant neighbor," the website said.
While CNPC may yet go forward with Line D, one possibility is that China has kept the option alive as an incentive for Russia to meet China's demands on a competitive pipeline deal.
In May, Russia's Gazprom signed a $400-billion (2.4- trillion yuan) agreement to supply CNPC with 38 bcm per year through a pipeline from eastern Siberia over a 30-year period, sealing a controversial deal after a difficult decade of talks.
It remains to be seen whether the Russian deal will ease China's drive to pursue the Line D project, or whether it may still be seen as needed to keep Russia on track to complete its pipeline by 2019.
But conflict between Kyrgyzstan and Tajikistan is likely to be another challenge for a plan that already faces questions, while China has yet to exert political power in Central Asia to ensure cross-border energy projects like Line D.