Question

nixon not only enunciated his own doctrine, but declared, echoing kennedy, that there could be no winners in a nuclear war, and embarked upon détente with the soviet union and arms - control treaties based upon equality.
in this sentence, doctrine means:
a stated government policy, especially regarding foreign affairs
the act of refuting some claim by offering a contrary argument
the process of preparing a nation for war
a statute in draft before it becomes law

Explanation:

The context of the sentence is about Nixon's actions in foreign affairs (detente with the Soviet Union, arms - control treaties). The word "doctrine" in a political (especially foreign policy) context is often used to refer to a stated government policy. The other options:

• "The act of refuting some claim by offering a contrary argument" is more related to a debate or argumentation process, not relevant to the political context here.
• "The process of preparing a nation for war" is about military preparedness, which is not indicated by the text (the text is about treaties, not war preparation).
• "A statute in draft before it becomes law" is about a legislative draft, which is not in line with the foreign - policy - related context of the sentence.

Answer:

a stated government policy, especially regarding foreign affairs