Under cover of darkness, China yesterday moved hundreds of its warships, fighter jets, tanks and soldiers to completely encircle Taiwan.

They sat in wait until the sun rose, then China's government declared on state TV and social media channels that it had begun its most extensive war games ever around the island.

The "Justice Mission" — as it was dubbed by Beijing — would showcase the military's capacity to surround the democratically governed Taiwan, conduct live fire and simulated strikes on land and sea targets, and launch drills to blockade the territory's main ports.

It had all the hallmarks of a wartime campaign.

Even the announcement was primed for maximum impact: glossy posters with powerful images of weapons and slogans, pre-recorded military speeches, carefully curated videos of battle-ready soldiers firing missiles off warships, and lengthy editorials about China's righteous fight to protect its interests from international interference.

China claims the independently governed Taiwan as its sovereign territory and has long-held ambitions to take control of the island.

When launching 10 hours of live-firing exercises today, China said it would demonstrate the military's resolve to "combat separatism and promote unification without hesitation".

So the message from Beijing was blindingly clear: Its military, the People's Liberation Army (PLA), is more ready than it's ever been to launch an attack on Taiwan.

But Taiwan wasn't the only, or even prime, intended audience of the warning.

It's likely a much more powerful foe was the target: the United States.

A warning against 'outside military intervention'

It was just a fortnight ago that the US agreed to a record-breaking $US11 billion ($16 billion) arms deal with Taiwan, pledging to provide the latest high-tech rocket-launchers, drones and tanks to bolster the island's self-defence against China.

Beijing was livid and promised "forceful measures" in retaliation, which have now come to be.

In fact, for the first time ever, China has explicitly stated the drills are targeting "deterrence of outside military intervention", in a pointed swipe at America.

China surrounded Taiwan on Monday, publishing this map of where sea and air restrictions would be in place. (Credit: Chinese People's Liberation Army)

One of the propaganda posters produced by Beijing appeared to show numerous vessels with ramps and open decks, which could be used to carry out an amphibious assault on Taiwan, emblazoned with the slogan: "Any foreign interference that touches the shield [of justice] shall perish! Any separatist scoundrels who encounter the shield shall be destroyed!"