The core lesson in the events leading to World War I is that a relatively minor incident (the assassination of an Austrian archduke in Sarajevo in late June 1914) can escalate into a war between great powers in a matter of weeks.
Rudd is obviously an astute observer of the region and has a lot of interesting things to say, however, I disagree with the above. WWI didn't just happen because of escalation over a minor incident. It happened because a malevolent power (Germany) already had a war plan that they badly wanted to execute, and they used a minor incident as a pretext for escalation. If it wasn't Ferdinand it would have been something else. In fact, Germany actually sidelined Austria-Hungary even after Russia had all but agreed to its demands in order to avert war, because averting war was never going to happen (and the war Germany wanted was against France--the Kaiser lobbied his cousin the Czar not to honor Russia's mutual defense pact with France). So it was two countries that had nothing whatsoever to do with Ferdinand's killing who were inevitably going to war.
So I think the real lesson is that we always need to look for ulterior motives. When one country is behaving irrationally in the aftermath of what should be a nothing event, then there's something else entirely at play (except maybe in the case of America, because Trump has no strategy). There are generally no irrational players in Great Power conflicts, there are only hidden motives. And China is definitely not going to do anything it doesn't see as being in its long term interest. They are not elected officials, plus they have a fixation on China's former greatness, so they therefore will more likely than not think in much longer term than we can afford to in the West. Misunderstanding one's adversary is a bigger mistake than overreacting to a minor aggression.