I know that Anthony Albanese became the first Australian prime minister to visit China in six years. But so what?

Oh, we now have "better relations" with China, say the media reports. But what is that supposed to mean, in concrete terms?

Well, it means improved trade access to China, people say - as if we want to restore our economic dependence on a country that has used trade as a weapon against us.

Anything else achieved? Anything specific? Or are we just supposed to be excited by the atmospherics of "better relations"?

Actually, there are some worthwhile advantages in getting along better with China. But they don't amount to much.

Meanwhile, there's a danger of us sacrificing national interest in order to maintain these pleasant atmospherics. In fact, there's a danger that the government already has done so, by deciding not to force the Chinese operator of Darwin Port to sell up.

Incidentally, placement in China's nightly national news broadcast suggests Albanese's visit wasn't a big deal to Beijing. He got coverage because the doings of China's top leaders are always reported, but on Monday Xi Jinping's meeting with him ranked fifth in the news line-up. It came behind the president's speeches at a couple of conferences and his glad-handing of the prime ministers of Cuba and Serbia.

As for the Australian-Chinese relationship, we have indeed wanted to take venom out it, but for reasons that don't attract much public attention. From time to time, we do need Beijing's cooperation.

For example, if an Australian gets into trouble in China, our consular officials will need to get involved with help from the Chinese Ministry of Foreign Affairs. Or maybe a load of Australian goods will turn up on a wharf one day with faulty paperwork; to sort it out, our people need responses from Chinese officials.

And in international meetings on dull but important regulatory matters, we'll sometimes want to persuade China to vote with us.

And that's about it. That's all we should want or expect from "better relations".

You might say that getting along better with China also reduces the likelihood of it seizing Australians as hostages, but taking such a view implies that we should be grateful for not being menaced.

Don't expect "better relations" to result in the Chinese military backing off in its aggression against our patrols of the South China Sea, nor will Beijing's intelligence services give up on trying to ransack Australian intellectual property.

As for revived exports, companies would need to see low costs or rich short-term profits before building up in the Chinese market. That makes us wonder about the wisdom of 250 Australian businesses that have just turned up at China's biggest trade exhibition, in Shanghai, to promote their products. Do those managers pay attention to international affairs as they spend shareholders' money?

It's not just about making a profit on each sale of goods and services while the opportunity lasts. Establishing a market presence costs money - for example, in advertising - and there's an opportunity cost of pushing products in China instead of somewhere else.

If China turns nasty again, as it easily could at any time, we trust that those businesses won't go running to the government, asking it to sacrifice national interest just so they're not stuck with mountains of unsold lobsters, plonk and university courses.

But we must wonder whether the government has already sacrificed national interest to achieve the hype of "better relations".

MORE AGE OF THE DRAGON:

Last month this column noted there was no sign of concessions from Australia having bought China's reduced hostility towards us. The change seemed to have come entirely from the Chinese side.

Maybe I spoke too soon. A few days later, the Department of Prime Minister and Cabinet announced that China's Landbridge Group would not be forced out of its long lease on Darwin Port.

The department issued a somewhat comical statement saying regulatory arrangements were enough to control the risks of Chinese ownership of the commercial facilities in Darwin.

So we can imagine a Chinese security operative infiltrated into the port reporting back to superiors in Beijing: "Listen, I can't conduct any espionage here or sabotage the joint, because the Department of Prime Minister and Cabinet says it would be against the law."

Anyway, Labor arranged for the department to carry out an overly narrow review. The biggest issue in Chinese operation of the port is not actually the direct security threat. Rather, it's the obliteration of our standing when we oppose other countries letting China control their infrastructure.

Landbridge's facility is in the same harbour as a naval base and would itself be needed for military purposes if we found ourselves at war. US forces exercise in Darwin, and we have one of our most important air bases there.

So how can tell the Solomon Islands, for example, that selling a port to Chinese interests would be unwise? We are hobbling even the US's influence with this ongoing blunder, since a small country tempted by a Chinese offer of investment can always reply, "Well, your good mate Australia did it, so why can't we?"

The Coalition government disgraced itself in 2015 by allowing Landbridge to take over the port facility. But Labor has done worse: in the past eight years the threat from China has become crystal clear, yet Labor is letting the mistake stand.

I do hope it didn't make that foolish decision just to achieve "better relations".