How do the Evil Iranians acquire British sailors and marines? By now, we should all know what the process is called: they "kidnap" them.
How does the Righteous USA obtain Iranian liaison types? We don't "kidnap" them, oh no. We detain them.
That's why they hate us. They hate us because we're so darned polite.
Update: Them British sailors sure do hate Amur'ka, don't they?