In an explanatory essay, or any essay, the introductory paragraph introduces (hence it's name) the main idea, or what you are going to explain. The body paragraphs go into extreme detail of what the introductory paragraphs mentioned.
Answer:
truman doctrine is the principle that the US should give support to countries or people's threatened by Soviet forces or Communist insurrection. The invasion of South Korea made Truman genuinely fearful that the Soviet union and China intended to expand the sphere of communism throughout Asia.
All Japanese arts pattern, such as tea ceremony, flower arrangement, calligraphy and even martial arts were highly influenced by the rare philosophy of Zen. These art designs were mold by Zen into a spiritual method focused on calmness, simplicity, and self-growth.