That's easy, huh? To make things more concrete, look at how long the EU was (and still is) dependent on Russian gas. Russia even used it to influence politics

That's easy, huh? To make things more concrete, look at how long the EU was (and still is) dependent on Russian gas. Russia even used it to influence politics by shutting off supply to Ukraine. Poland, along with its non-German neighbors especially, have been working to diversify their supply to prevent that, but it basically took the war in Ukraine to push Europe in that direction (and even then, reluctantly; take Germany for example). Or consider the case where your economic partner is much larger economically (like US in relation to Mexico). Who do you think has more weight at the negotiating table? Who has more money to influence political realities? Who can take a bigger hit? There is mutual dependence, but the relationship is not symmetrical. It's easy to say GFYS, but often difficult to do in practice. First, there has to be an alternative, second, you have to migrate to that alternative. This can be costly if not practically impossible until a contender emerges: he'll have your back against the other, but now you're their vassal, so to speak. Some call this phenomenon "neocolonialism"; Picketty also uses the term "foreign-owned countries". You get lodged in a web of incentives. You always are. Right now, the China-US dependent is something like: the US needs China for cheap labor and cheap goods, but China needs the US to buy all these things to fuel its economy. The balance can eventually tip and shift, however. Indeed, that's what BRICS is about.