First, by yielding to what in the end was unbearable political pressure, he has reinforced to Beijing, and to its wealthy business and political surrogates here, that Australia will safeguard its sovereignty as jealously as does China.

Second, via his high profile rise and fall, the 34-year-old wunderkind has provided a brutal human lesson. Politicians seen to be influenced by a foreign power will be of no durable value to that government because their credibility will evaporate, and their sponsors exposed and neutralised.

And third, despite being personally crushed, Dastyari has departed without rancour thus salvaging some honour - given his pitiable circumstances. He did this by rejecting (for the record) doubts over his Australian patriotism, reaffirming his commitment to the ALP, and thanking the leadership that had persevered with him.

Of course, Bill Shorten and Penny Wong had done so in the fervent hope that the young senator would do the right thing.

That judgment proved correct, but not before Shorten's otherwise stellar year tumbled headlong into the Dastyari-China-national security quagmire.

The Labor claim that Dastyari had already paid for his Huang Xiangmo links because he'd been dropped as deputy opposition whip in the Senate, was always hopelessly inadequate.

These were serious allegations and included the revelation that even after his demotion for soliciting money from the billionaire benefactor to cover travel costs, Dastyari had visited Mr Huang and advised inter alia about Australian security agency surveillance.

Despite his huffing, Shorten had been left looking impotent, fuelling the suspicion that Dastyari's power in the infamous New South Wales Right, exceeded his - that the leader could not sack the junior senator because of what it might cost him.

The government was never going to allow that to go unremarked, much less the suggestion of shadowy Labor links to the cashed-up Chinese Communist Party.

In recent days, Coalitionists had ratcheted up their attacks using hyperbolic terms such as "treasonous" and "double agent".

A final observation. By falling on his sword before Christmas, Dastyari has stemmed Shorten's bleeding. That much is good for Labor in 2018 but the affair, on the eve of the Bennelong byelection has also reminded Sydney voters of the ugly side of New South Wales politics where business types, hefty donations, and murky dealings are all too common.