Differences are astonishing. It's Ok for a despotic country to murder their property, or property of some other country when net effect is positive for them. For them, it's like a plantation: if we cut some trees, or cut grass, then net yield from field will increase, so lets do it. If you are good plant and in good place, you will be left. If not, you will be cut.

For example, it's Ok for Russian Federation to kill their own or foreign people (e.g. British citizens), or start a war just to increase their profit from their natural gas.

Are you positive western democratic republics don't murder and/or start wars for profit ? Last I heard the USA's army and secret services were pretty active.

What's different about their armies and ours ? I mean when was the last time citizens of a democratic republic gave their input on what assassination to carry out or war to wage ?

There is definitely a point about overt, extreme abuse against their own citizens being mostly prevented by representative democracy. But nothing about general consent or agency.

A lot of differences:

- No eternal leaders. - Freedom of expression - Separation of powers that limit each other

>No eternal leaders.

Oh? https://en.wikipedia.org/wiki/List_of_monarchy_referendums

>Freedom of expression

Oh? https://en.wikipedia.org/wiki/Ursula_Haverbeck

Apart from "No eternal leaders", I don't think these are specifically attributable to representative democracy.