In a post-B.E.P.S. world, aggressive tax planning is a mortal sin.  If a principal purpose or a main purpose of entering a transaction is tax avoidance, the tax benefits are lost.  A ruling in a recent pre-trial hearing in the U.S. Tax Court addressed a clearly abusive transaction aimed at importing high-basis, low-value assets into a U.S. partnership so that the U.S. investors could benefit from losses on nonperforming loans.  The I.R.S. moved for summary judgment in its favor, but the motion was denied.  Under applicable case law, a transaction can be respected even if it is tax motivated as long as economic substance is present.  Consequently, the taxpayer is entitled to a day in court, even if the prospect of victory is slim.  Rusudan Shervashidze and Stanley C. Ruchelman compare the approach followed by the U.S. Tax Court with the principal purpose test rules of the A.T.A.D. and B.E.P.S.