China has been accused of intensifying its pressure campaign on Taiwan after installing drilling platforms and energy vessels inside the island’s exclusive economic zone (EEZ) Oilprice.com reports. The move, linked to the state-owned China National Offshore Oil Corporation (CNOOC), is being interpreted by analysts both inside and outside the region as a major escalation of Beijing’s “grey-zone” strategy – tactics designed to test Taiwan’s resilience without crossing into outright warfare.

Taiwan already sees daily moves by China to intimidate with flights into Taiwanese airspace and Chinese naval vessels circumnavigating the main island of Taiwan.

In recent weeks, Taiwanese military surveillance has detected at least a dozen CNOOC vessels and fixed structures operating within Taiwan’s EEZ, according to reports cited by The Guardian. Among them is a drilling platform just 50km from waters surrounding the Pratas Islands, which are controlled by Taiwan. Steel “jackets” which serve as the foundations of offshore oil rigs have also been spotted the report adds.

This latest step in an ongoing campaign against Taiwan by Beijing now indicates a shift towards embedding permanent infrastructure in disputed areas, effectively normalising China’s presence in Taiwan’s waters and in turn allowing China to ‘steal’ Chinese energy sources.

The Global Taiwan Institute argues that these “grey-zone” tactics are designed to probe Taipei and its allies, stretching their ability to respond while avoiding a conventional confrontation. The approach also helps Beijing incrementally expand its reach under the cover of ambiguity.

Taiwan’s energy dependence at present leaves it acutely exposed to Chinese coercion. Domestic production of gas and oil is negligible and imports supply virtually all the island’s oil, gas and coal. This vulnerability was only added to in May when the ruling Democratic Progressive Party in Taipei shut down its last nuclear power plant, fulfilling a campaign pledge made after Japan’s 2011 Fukushima disaster.

As such, Beijing now appears to be exploiting this reliance. Taiwan’s EEZ offers some potential hydrocarbon resources, but China’s activity risks blocking Taipei from accessing them.

A think tank in Washington earlier in the year modelled the potential consequences of a blockade. A series of 26 wargames conducted by the Center for Strategic and International Studies (CSIS) concluded that Taiwan’s natural gas reserves would be exhausted within 10 days of maritime disruption the Oilprice.com report adds. Coal stocks would run dry in just seven weeks, and oil supplies in roughly 20 weeks. In short, Taiwan would be crippled by any form of Chinese blockade. It is not an issue on the minds of many in Taiwan however, and rarely features in news or public opinion debates.

But the implications for the island’s grid would be severe, with electricity output potentially dropping to one-fifth of normal levels. To this end, China’s attempted installation of oil and gas rigs so close to Taiwanese territory is seen not only as a challenge to sovereignty but also as a calculated reminder of Taiwan’s energy fragility.

And by placing energy platforms in contested waters, China is signalling both defiance of international rulings and a willingness to tighten the squeeze on Taiwan.

The installation of CNOOC platforms may appear technical – for now - but for Taiwan the strategic risks are stark.