For the first time, Beijing has stopped mainlanders from traveling to Taiwan on their own. Although there are precedents for the central government to limit its citizens' access to the island, past restrictions were confined to group tours.
The latest curb may be interpreted as a reaction to the Americans' "provocation" in selling advanced M1 tanks and immensely upgraded F16 warplanes to Taiwan. It also has everything to do with Taiwan's presidential election in January.
The edict - with immediate effect - reveals a sense of restlessness in Beijing that Taiwan's pro-independence President Tsai Ing-wen, who is currently leading in a major opinion poll, will secure a second four-year term.
Beijing's statement means that mainlanders can continue visiting Taiwan - but only via tour groups.
Kaohsiung Mayor Han Kuo-yu, who is the opposition Kuomintang party's candidate in the presidential sweepstakes, has cast himself as Beijing's favorite, with his visit to the central government's liaison office during a recent trip to Hong Kong.
The individual travel ban is extraordinary in the sense that, while the mainland has no control over where the individuals may go, those traveling there in organized groups will have to follow pre-approved itineraries.
Most likely, KMT-controlled municipalities will keep hosting busloads of sightseers from the mainland to boost the local economy, whereas others run by the ruling Democratic Progressive Party will suffer.
The impact can be substantial since half of the mainland arrivals are made up of individual travelers. The message is clear: KMT spells prosperity, while DPP means the doldrums.
Nonetheless, there's still a sense of urgency in Beijing's announcement.
In the latest poll by My Formosa news website on the question of "who is suitable to be the next president," Tsai is leading in all probable combinations of candidates.
There are numerous opinion polls in Taiwan, but the My Formosa version is considered the most authoritative among serious public affairs commentators.
In a one-on-one match between Tsai and Han, the incumbent would be backed by 46.4 percent of respondents and Han by 37.2 percent, with the remainder undecided.
If it's going to be a four-way contest among Tsai, Han, Taipei Mayor Ko Wen-je and Foxconn tycoon Terry Gou Tai-ming, Tsai would come out on top with 30.6 percent, followed by Han in second, and Ko and Gou third and fourth.
A three-way matchup involving Tsai, Han and Gou would still see Tsai on top with 36.1 percent support.
My Formosa's poll confirmed an earlier observation that when Han won the KMT's telephone polls to secure the party's nomination, his unexpected large winning margin was influenced by DPP supporters pretending to be voting for the KMT during the telephone polls, as the ruling DPP was believed to be more fearful of facing Gou than Han.
Since Hong Kong's protests against the extradition bill spread to Taiwan, public trust in Han dropped to all-time lows in June and July.
It's impossible for Beijing policymakers not to be concerned about this alarming development.
Therefore, it's probable the central government will formulate more tactical measures between now and January to back Han's bid.