We measure the period and spin-down rate forSGR&hthinsp;1900+14during the quiescent period two years before the recent interval of renewed burst activity. We find that the spin-down rate doubled during the burst activity, which is inconsistent with both magnetic dipole driven spin-down and a magnetic field energy source for the bursts. We also show thatSGRs&hthinsp;1900+14and1806−20have braking indices of ∼1, which indicates that the spin-down is due to wind torques and not magnetic dipole radiation. We further show that a combination of dipole radiation and wind luminosity, coupled with estimated ages and present spin parameters, imply that the magnetic fields ofSGRs&hthinsp;1900+14and1806−20are less than the critical field of4×1013&hthinsp;Gand that the efficiency for conversion of wind luminosity to x-ray luminosity is <2&percent;. ©2000 American Institute of Physics.