answer:
well, it's complicated..
explanation:
japan–united states relations (米日関係 beinichi kankei) refers to international relations between japan and the united states. relations began in the late 18th and early 19th century, with the diplomatic but force-backed missions of u.s. ship captains james glynn and matthew c. perry to the tokugawa shogunate.
the countries maintained relatively cordial relations after that. potential disputes were resolved. japan acknowledged american control of hawaii and the philippines and the u.s, reciprocated regarding korea. disagreements about japanese immigration to the u.s. were resolved in 1907. the two were allies against germany in world war i.
starting in 1931, tensions escalated. japanese actions against china in 1931 and especially after 1937 during the second sino-japanese war caused the united states, along with its allies britain and the netherlands, to cut off the oil and steel japan needed for her military conquests, japan responded with attacks on the allies, including the surprise attack on pearl harbor on december 7, 1941, which heavily damaged the us naval base at pearl harbor, opening the pacific theater of world war ii. the united states made a massive investment in naval power and systematically destroyed japan's offensive capabilities while island hopping across the pacific. to force a surrender, the americans systematically bombed japanese cities, culminating in the atomic bombings of hiroshima and nagasaki in august 1945. japan surrendered, and was subjected to seven years of military occupation by the united states, during which the american occupiers under general douglas macarthur eliminated the military factor and rebuilt the economic and political systems so as to transform japan into a democracy.
in the 1950s and 1960s japan, while neutral, grew rapidly by supplying american wars in korea and vietnam. the trade relationship has particularly prospered since then, with japanese automobiles and consumer electronics being especially popular, and japan became the world's second economic power after the united states. (in 2010 it dropped to third place after china).
from the late 20th century and onwards, the united states and japan have firm and very active political, economic and military relationships. the united states considers japan to be one of its closest allies and partners.[1][2] japan is one of the most pro-american nations in the world, with 85% of japanese people viewing the u.s. and 87% viewing americans favorably in 2011, 73% viewing americans favorably and 69% viewing the u.s. favorably in 2013, and 75% viewing americans favorably and 57% viewing the u.s. favorably in 2017.[3] most americans generally perceive japan positively, with 81% viewing japan favorably in 2013, the most favorable perception of japan in the world, after indonesia.[4]