Final answer:
The best example of extended deterrence among the given options is the nuclear umbrella, which includes security pacts where one state extends its defense commitments to protect another state, often involving a promise of nuclear defense to deter potential attacks.
Step-by-step explanation:
The best example of extended deterrence in the current international political alignment is b) Nuclear umbrella. Extended deterrence refers to the protective shield one state may promise to another, in which the protector state extends its own defense commitments to include the protected state, such as via security pacts. These security pacts, making up a nuclear umbrella, act as a guarantee of military protection, often including the promise of nuclear defense, aimed at deterring potential enemies from attacking the protected state or its allies.
International agreements, like those forming the North Atlantic Treaty Organization (NATO), are prime examples of such pacts where extended deterrence plays a crucial role. While economic sanctions, diplomatic negotiations, and peace treaties are important foreign policy tools and outputs, they do not represent extended deterrence as accurately as the provision of a nuclear umbrella because they do not involve a direct promise of military protection from one state to another.
Thus, among the options, a nuclear umbrella provided by a state or coalition of states serves as the strongest and most direct form of extended deterrence, often influencing the behavior of other states in the international system and preserving the status quo or fulfilling commitments to international treaties for the good of the international system as a whole.