Realism starts with a cold, hard fact: the international system is . This doesn't mean it’s chaotic, but rather that there is no "world government" or higher authority to protect states if they are attacked.
: States can never truly know if another country is a "status quo" power or an aggressor. A peaceful neighbor today could become a threat tomorrow. 2. Three Pillars of Realist Fear
: When State A builds up its military for defense, State B perceives this as a threat and builds its own. This creates a cycle where both states feel less secure than before, despite their best efforts.
Because states must provide for their own security (a "self-help" system), two critical factors emerge: