knee-jerk (adj.)
unthinking, reflexlike
from: knee jerk (noun), an outward reflex kick of the lower leg caused by a sharp tap on the tendon just below the kneecap

Link to present incidents:
“We need to make strategic decisions on immigration, not knee-jerk ones that fail to take account of the needs of the economy.” Mark Hilton from London First, a non-profit, pro-business organisation, in answer to the immigration minister, James Brokenshire, who had said the figures showing net migration at 220,000 higher than the government’s 100,000 target – and rising – were “deeply disappointing”.