Embargoes aren't used much anymore. Countries use tariffs. Which the US has shown are actually quite effective against China, because China has a legitimate fear of competitors springing up elsewhere since once they exist they may continue to exist even after the tariffs are gone.
So they respond by devaluing their currency to remain competitive even against the tariffs, which is equivalent to paying the tariffs rather than passing the cost on to the customers. But then your own citizens don't feel the pinch from the tariffs and you can maintain them indefinitely, or even increase them, until you get what you're asking for.
That assumes you're a large enough player to get them to respond that way, but smaller players can form coalitions.
So they respond by devaluing their currency to remain competitive even against the tariffs, which is equivalent to paying the tariffs rather than passing the cost on to the customers. But then your own citizens don't feel the pinch from the tariffs and you can maintain them indefinitely, or even increase them, until you get what you're asking for.
That assumes you're a large enough player to get them to respond that way, but smaller players can form coalitions.