Chinese Bombers Threatening Because they Are highly Visible

Pete's Comments

So China has publicized the ability of its H-6K bombers to very temporarily operate (ie. land and takeoff) from Woody Island is more symbolic of visible power projection into the South China Sea (SCS) than a fundamentally new threat. 

The whole SCS and surrounding nations can already be hit with more stealth and surprise by Chinese missiles from other platforms, including MRBMs, IRBMs, SLBMs and extended range SLCMs. Chinese surface ships, air-refueled jet fighters and land based cruise missiles on the islands themselves could already fire missiles at some or all of these SCS targets. 

It is highly public threats, even from mainly old technology, very unstealthy, bombers, like the H-6K, that can cause anxiety in nations that have only modest anti-aircraft capabilities and generally no 

anti-missile capabilities. The H-6Ks very visibility represent public and political threats. This is similar to the highly visible threat from US aircraft carrier groups when compared to the invisible and more potent threat from cruise and ballistic missile carrying US submarines.

OTHER COMMENTS

I've added links to useful comments on May 22, 2018 from:

KQN: “China is gradually enforcing its claim on the SCS. The Nine-Dash Line has morphed into a solid line. It is a well thought out strategy, reinforcing your territorial claims with less than subtle threats to neighboring countries, achieving your strategic goals while avoiding open conflicts (which would threaten the economic well being of all). We can already predict H-6K's will be landing next in the Spratly's. Fiery Cross, Subi and Mischief reefs all haveclass A runways, as long as the one on Woody. [See Airport Table below]. Several reinforced hangars there are large enough for them. That will put Northern Australia and Guam within range.” [see map below].

and

Josh “The H-6K is aerodynamically similar to previous H-6s and Tu-16s, but the use of modern turbofans (of Russian manufacture - the Soloviev D-30s) give it a much greater range and payload. That said it is still a regional bomber, not an intercontinental one. Australia for instance would be out of practical range of even cruise missiles without midair refueling.”

The upper set of blue-black dots are potential H-6K bomber Paracel Island takeoff points, including Woody Island Air Base [see Table below]. These points put all of the South China Sea, Taiwan, Philippines, Vietnam, Laos, Cambodia, Thailand, Malaysia and Singapore within the "combat radii" of the bombers' once the bombers land attack and anti-ship cruise missiles are fired.

(Map courtesy CSIS) 

The lower set of dots represent H-6K bombers launched from China's Spratly Island air bases (see Table below) with combat radii extended by cruise missiles (and mid-air refueling) are able to hit all of Indonesia as well as Darwin, Australia 

AIR BASES TABLE for Spratly Islands (source) and Woody Island (in Paracel Islands)

Location	Occupied by	Name	Built	Length	Notes
Taiping Island on Spratly Islands	Taiwan	Taiping Island Air Base	2007	1,200 m (est.)	Military use only. No refuel facilities. [1]
Swallow Reef on Spratly Islands	Malaysia	Layang-Layang Air Base	1995	1,367m	Dual-use concrete airport.
Fiery Cross Reef on Spratly Islands	China	Yongshu Air Base	2016	3,300m (est.)	Dual-use concrete airport.
Subi Reef on Spratly Islands	China	Zhubi Air Base	2016	3,300m (est.)	Dual-use concrete airport.
Mischief Reef on Spratly Islands	China	Meiji Air Base	2016	2,700m (est.)	Dual-use concrete airport.
Thitu Island (Pag-asa) on Spratly Islands	Philippines	Rancudo Airfield	1975	1,300m (est.)	Concrete.[2]
Spratly Island (Trường Sa) on Spratly Islands	Vietnam	Trường Sa Air Base	1976-2016	1,200 m (est.)	Military use only.
Woody (Yongxing) Island in Paracel Islands	China	Yongxing Island Air Base	1990	2,700m	Dual-use concrete airport

Even in aerial bomber capabilities symbolism counts.

Pete, KQN and Josh