Final answer:
State B violates the sovereignty of State A by invading it, challenging the principle of state control over its affairs without external interference.
Step-by-step explanation:
When State A is invaded by State B, State B is said to have violated the sovereignty of State A. Sovereignty is a fundamental principle that acknowledges the full right and power of a governing body over itself, without any interference from outside sources or bodies.
The concept of sovereignty is entrenched in international law and implies that states are legally equal, each possessing the same rights and duties in the international community. This includes the right to self-determination, territorial integrity, and non-interference in the internal affairs of the state. Sovereignty allows a state to conduct its affairs, such as creating and enforcing laws, without external control. When another state invades or interferes, it challenges this principle, potentially leading to consequences under international law.