In general, Canada is a stable country.
The antonym of stable is unstable.
Iraq is somewhere between stable and unstable. Iraqi Kurdistan in particular is rather stable with minimal insurgent activity. Central Iraq is more problematic. Iraq is not a developed country, but a developing country.
stable
cuba is stable
stable
Unstable.
The opposite of stable is unstable or variable.
Unstable
Selenium is generally considered stable in its elemental form. However, some of its isotopes are unstable and undergo radioactive decay.
Critical Unstable Potentially Unstable Stable
A stable system is one that holds stability and is dependable. An unstable system is just the opposite. You do not know what to expect from an unstable system; it is not close to being dependable.