WASP-12 is a hot Jupiter system with an orbital period of $P= 1.1textrm{ day}$, making it one of the shortest-period giant planets known. Recent transit timing observations by Maciejewski et al. (2016) and Patra et al. (2017) find a decreasing period with $P/|dot{P}| = 3.2textrm{ Myr}$. This has been interpreted as evidence of either orbital decay due to tidal dissipation or a long term oscillation of the apparent period due to apsidal precession. Here we consider the possibility that it is orbital decay. We show that the parameters of the host star are consistent with either a $M_ast simeq 1.3 M_odot$ main sequence star or a $M_ast simeq 1.2 M_odot$ subgiant. We find that if the star is on the main sequence, the tidal dissipation is too inefficient to explain the observed $dot{P}$. However, if it is a subgiant, the tidal dissipation is significantly enhanced due to nonlinear wave breaking of the dynamical tide near the stars center. The subgiant models have a tidal quality factor $Q_astsimeq 2times10^5$ and an orbital decay rate that agrees well with the observed $dot{P}$. It would also explain why the planet survived for $simeq 3textrm{ Gyr}$ while the star was on the main sequence and yet is now inspiraling on a 3 Myr timescale. Although this suggests that we are witnessing the last $sim 0.1%$ of the planets life, the probability of such a detection is a few percent given the observed sample of $simeq 30$ hot Jupiters in $P<3textrm{ day}$ orbits around $M_ast>1.2 M_odot$ hosts.
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