It is proven that the Wahlquist perfect fluid spacetime cannot be smoothly
joined to an exterior asymptotically hat vacuum region. The proof uses a po
wer-series expansion in the angular velocity, to a precision of the second
order. In this approximation, the Wahlquist metric is a special case of the
rotating Whittaker spacetime. The exterior vacuum domain is treated in a l
ike manner. We compute the conditions of matching at the possible boundary
surface in both the interior and the vacuum domain. The conditions for matc
hing the induced metrics and the extrinsic curvatures are mutually contradi
ctory.