That's true so long as everyone is dependent on each other. If, everyone is dependent on one country, that doesn't hold
China has a near monopoly on a lot of production. Countries that depend on them certainly won't go to war with them, but that doesn't hinder China from starting a war with those countries, and even gives them an advantage. And it doesn't stop dependent countries from warring with each other and that could even be beneficial to China.
N.B. I use China as an example only. Replace China with any country that might have a near monopoly on production of some kind. The point I'm trying to make isn't "ahhh China scary", it's that interconnectedness may only prevent war if it's actually interconnected, and not a monopoly.
Trade goes both ways. The seller of goods is just as dependent on the exchange as the buyer. Nobody stays in business going to war with their customers. And there are truly very few products that cannot be sourced from alternates given a little time and money.
I think the "global interdependence reduces war" hypothesis is pretty strong.
Money is fake in a way that physical products aren't. So the parties have very unequal bargaining positions, the one with the "real" stuff (products) can walk away much more easily than the one with the "fake" stuff (money).
And if the seller is a monopoly on a critical good while the buyer is a tiny fraction of their business, the relationship is asymmetrical and the seller won't suffer nearly as much from a war.
China has a near monopoly on a lot of production. Countries that depend on them certainly won't go to war with them, but that doesn't hinder China from starting a war with those countries, and even gives them an advantage. And it doesn't stop dependent countries from warring with each other and that could even be beneficial to China.
N.B. I use China as an example only. Replace China with any country that might have a near monopoly on production of some kind. The point I'm trying to make isn't "ahhh China scary", it's that interconnectedness may only prevent war if it's actually interconnected, and not a monopoly.