I think rainpizza put it the best here: https://lemmygrad.ml/post/10742177/7761032
To enforce that economic blockade, you have to declare war to the entire West and decouple completely from the Western system(USD, SWIFT, Maritime Shipping Routes, et all).
As long as the West is willing to save their Zionist dog by bleeding their economies dry, there is no viable way to do an economic blockade without a military siege.
The problem with people here is that they see the entity as something separate rather than something within the Western system. To eradicate Israel, you have to destroy the West.
(bold emphasis mine)
In other words, we cannot take the western empire out of the picture and try to understand China's dealings with israel as dealing with a purely sovereign, independent entity (because that's not what it is). We have to understand it in relation to israel's dependence on / connection with the US. When we put it in that way, it's easier I think to understand that the question is not one of distancing from israel, but distancing from the west, and actively doing that is a valid choice for an AES state to make but it's not the path China took when they focused on building up their productive forces and becoming the productive powerhouse that they now are. For them to go a different way has much broader implications than trade with any one nation and needs to make sense in the context of how they're engaging with unipolar capitalism and the dynamics of global trade in order to develop toward multipolar. Were they equipped to reject the west and its genocidal ways on a broader scale, I would expect that israel would only be the tip of the iceberg and they would have a million excuses to do so with the way the west treats them and others.
So then the question becomes why? The cynical ultra-left view seems to be something like that they're not rejecting the west because they benefit from the trade deals or something. But the west wants to undermine them no matter how they try to work for mutual benefit and the evidence points to them still being thoroughly led by communist principles. So the ultra-left view doesn't make sense. You have to essentially believe they are either stupid or compromised on a large scale, while still putting on a face like they aren't, both of which reek of racism that the Chinese people are incapable of recognizing internal threats and acting competently.
I think the ML answer is that the west wants to isolate and encircle them, always has, and China does not (yet) have the power to cut the west out, rather than be cut out by the west, if it comes to that; in bits and pieces maybe, and we saw some of that in the way China handled the attempted browbeating from the US with tariffs. But I think it's still in a fragile rather than well-established state. And until the balance of power shifts enough away from western economic dominance, China playing fast and loose with rejecting trade partners means cutting themselves out of deals that could broaden their influence and weaken the west's. This after they have worked really hard to forge the trade connections they have in the world.
I could imagine a counter argument regarding proxies going something like: Well what about Ukraine with Russia? Russia intervened militarily in Ukraine, in spite of it being a proxy of the west. But Ukraine wasn't always a proxy, it took a long time for all out war to happen including from the west sabotaging peace deal efforts, including from Ukraine being an aggressor in the donbass, and this in the context of Ukraine being near Russia. The closest comparison for China would probably be when the US was openly at war in Korea, the Korean liberation forces were trying to fight them back and they asked for help from China and China of the time stepped in militarily. It was not only a matter of helping those in need, but it would have also been dangerous for them to have the US knocking on their doorstep next.
What's happening to Palestine is unquestionably horrific, but it's also far from the first time the west has done genocidal things. I think it seems unprecedented in its way largely because of how televised in real-time a genocide it has been. But the destruction itself is already characteristic of colonialism for hundreds of years and the imperialism form that developed after. If China treated it like an anomalous level of evil that has never been done before and threw massive weight behind trying to stop it as a result, they would be ignoring everything else the west has gotten away with and how important it is to ensure its power falls as a whole, not just through one proxy.
Is there a better way than what they are doing? Maybe analysis would show there is, I don't know. But there are other countries and peoples who are more closely positioned to oppose what's going on, namely those in the west, whose trade deals and leadership actively manufacture support for genocide day in and day out.
This is an interesting point because the key here is the USSR doesn't exist anymore. And for quite a few of us in these spaces, it probably never existed while we were alive (or not while we were cogent adult beings). The USSR as a world savior simply never existed. As impact beyond itself goes, the USSR made a huge difference in defeating Nazi Germany and being the first to establish a socialist state project, but it also took massive losses in the process of fighting Nazi Germany and was stretched thin from that and its international efforts. Meanwhile, the US was positioned really well after WWII to steamroll over the planet, utilizing pre-existing colonial and imperial tendrils to make it all the easier to do so.
In other words, what I'm trying to say is that although the USSR did great things for people, it was still heavily limited by its material conditions. And if it was still around today, it would be getting criticized by ultra-leftists in similar ways to how China is criticized now. Because it wouldn't be making all of the most plainly "moral" decisions, it would not be saving the world but instead acting in a complex way that tries to move the international and local cause of liberation forward, and the western empire propaganda machine would be telling people from day one to despise everything it stands for.
Here the Christian culture that Jones Manoel talks of rears its head again. Now that the USSR is no more, we can freely romanticize what it was, in a form unmarred by complex and uncomfortable realities. We can wallow in the comfort of the idea untouched and untainted by good will having to work within circumstances full of cruelty and neglect. It's reassuring in a way to hide in the purity of the idea, if one believes that acting within a cruel world, rather than rejecting it with the most swift and bridge-burning measures, has an inevitable corrupting influence that destroys otherwise good efforts or damns one (if not the whole world) to depravity.
Likewise with praise of China. It is dangerous (to their comfort) for the purist to sincerely learn about China in detail because the ideal will be shattered in favor of the material realities. The Christian-influenced conclusion will lead to the belief that it has been "corrupted". It is then knocked down from the pedestal that it never asked to be on, where it can be spat upon like a fallen angel who seeks to lead lost souls astray.