Critically discuss if government interventions to alleviate poverty are sustainable over a long period of time

I don't believe so.
Government intervention (such as welfares) is actually a good policy to help poor people sustain themselves for a short period of time .
But, in order to fully eliminate their poverty, the government have to eventually Help those people get a good job to sustain their own living, otherwise, the Government just hemorrhaging expenditures and increases national debt overtime.

Ifound this on google “separation of powers. a fundamental principle of the united states government, whereby powers and responsibilities are divided among the legislative branch, executive branch, and judicial branch.” i hope this you for what your looking for

The ceremonial column.