The field energy and magnetocapillary instability of isothermal incompressible and inviscid nonconducting liquid jets in a uniform magnetic field are considered. The equivalence between static and dynamic approaches at the onset of instability and cutoff wavelength is shown and its implications are discussed. A new dispersion relation for magnetocapillary instability in such jets is derived. This relation differs from that given in the literature. The existence of a critical magnetic field that stabilizes jets with finite susceptibility is established. It is shown that the jet is stabilized by the field irrespective of its being para- or diamagnetic, but the extent of stabilization is different. (C) 2004 Elsevier Inc. All rights reserved.