Concept:
Different political systems vary according to how power and authority are exercised.
Step 1:
Authoritarianism is a system where political power is concentrated in the hands of a ruler or a small group.
Step 2:
Such governments limit political freedoms and do not derive legitimacy directly from democratic participation.
Step 3:
• Capitalism is an economic system.
• Assimilation refers to cultural integration.
• Liberalism is a political philosophy supporting individual rights and democracy.
Step 4:
The question specifically refers to a non-democratic and non-republican government system, which matches authoritarianism.
Step 5:
Hence, the correct answer is Authoritarianism.
\[
\boxed{\text{(4) Authoritarianism}}
\]