  It has been conjectured and proven that entanglement island is not consistent
with long-range (massless) gravity in a large class of spacetimes, including
typical asymptotically anti-de Sitter spacetimes, in high spacetime dimensions.
The conjecture and its proof are motivated by the observation that existing
constructions of entanglement islands in high dimensions are all in
gravitational theories where the graviton is massive for which the standard
gravitational Gauss' law doesn't apply. In this letter, we show that this
observation persists to lower dimensional cases. We achieve this goal by
providing a unified description of the gravitational Gauss' law violation in
island models that can work in any dimensions. This unified description teaches
us new lessons on entanglement islands and subregion physics in quantum
gravity. We focus on the case of the (1+1)-dimensional Jackiw-Teitelboim (JT)
gravity for the purpose of demonstration.
