What they're explicitly looking for is a way of sentencing people to death in absentia. They don't care about retaliation, because they're EXPLICITLY looking for a stick to use against people they feel are to dangerous to live - that the worst case scenario is that they're alive tomorrow.
They aren't talking about general practice for what you do when you want to bring in Mad Hatter, they're talking about how they will peruse their already intended policy of, for instance, making sure Witch Boy can't rack up hundreds of thousands of dead children as a distraction. That the next time Mongol uses a Sun Eater to try and snuff out Sol, they can say 'This person is to dangerous to live, and so we're now pursuing every available avenue to fix that.'
Whether or not that's a good idea is a different discussion, but we're currently talking about how you sentence execution without trial. And the answer is that... you already basically can, with only a fig leaf.