The answer is "Nature"
The scene described in Walden focuses heavily, if not exclusively, on nature and the effect that the natural wonder of Walden Pond had on Thoreau. This is also the most key element of Transcendentalism: the search for enlightenment not in man-made society but in the natural world.
1) "... the distance of Hawaii from Japan makes it obvious that the attack was deliberately planned many days or even weeks ago... [during which] the Japanese Government has deliberately sought... [false] hope for continued peace."
2) "The attack yesterday on the Hawaiian Islands... American ships have been reported torpedoed..., [and] yesterday the Japanese government also launched an attack against Malaya.. Last night Japanese forces attacked the Philippine Islands..."
The first excerpt shows that Japan gave the US a false sense of hope by saying they are reigning in their expansions and hope to continue to have peaceful relations with the United States. The second excerpt then shows what Franklin was talking about, in that they used the 'guise of peace to backstab the US in hopes of continuing their expansion eastward.
I would say tense and uncomfortable because "it was undoubtedly hot" "he began to sweat" "began to throb in his ears" the sweat and heat makes it very uncomfortable also, the rumbling and throbbing sound makes it tense.
hope this helps :D