If you're at war then declare war. You get sweeping powers to deal with existential threats. Go ahead and declare your country is at war. Is it?

If you declare war without there being a bona fide casus belli, you'll be whisked out of power so fast your head will spin. See e.g. https://en.wikipedia.org/wiki/2024_South_Korean_martial_law_...

If you don't declare war, you don't get those emergency powers. You only get peacetime powers.

Russia loves to go right up to the line, and then cross it a little bit, just to antagonise you. But unless you're willing to be the instigator of WW3, you'll stick to peacetime powers and peacetime courts with peacetime standards of evidence

People love this 'expediency' for what they want, but once you destroy the rule of law and reason generally, nothing protects you.

You're standing in a forest, lighting a forest fire to kill the other guy. There is lots of history about this most fundamental error.