Nobody is blockading China.
All that is happening now is that we are forcing them to compete on the same terms every other country is.
A blockade is a causis belli. No doubt.
They aren’t going to go to war declaring, “The US no longer allows us to steal their technology, impose unbalanced, unanswered tariffs, and then dump our products into their markets.”
Nice summary. Trump's name did not come up but his fingerprints are all over this. What we're seeing here is the largest manufacturing nation in the world attempting to flex its muscles as a consumer nation. That, given the ongoing (and inevitable) diaspora of manufacturing to everywhere from Malaysia to Lesotho, may well be in its long term interest but we're talking decades there - or are we? Because China has discovered what it means for a manufacturing nation to be so dependent on oil producers, where the role between manufacturing customer and producer is now switched. For now the effect is blunted by the fact that low oil prices are in China's interest but it is clear that they are not under its control, and for an autocratic government that is threatening indeed. And all the while looms Trump, with his hands on the controls of both, albeit to a limited (but very significant) degree. China would love to attain that position if only for its independence. And that may be, at least partially, what this is all about.
Prior to WW2, we embargoed Japan from scrap metal and oil because of their brutality in China. As a result Japan, with no such resources of her own, was facing economic calamity. This, at least in part, precipitated Pearl Harbor.
We are not embargoing the PRC, but we are pressuring it economically and their economy is not nearly as robust as they project.
Will they attack us? Depends. China has a lot more resources to draw upon. But it pays to remember December 07, 1941, whenever you pressure a country that thinks it is your peer.