Comment on ``Magnetic-Field Enhancement of Superconductivity in   Ultranarrow Wires''
  The authors of a recent Letter [Phys. Rev. Lett. 97, 137001 (2006)] observed enhancement of the critical supercurrent of superconducting nanowires in external magnetic field. They attributed the obtained behavior to the presence of magnetic moments in the samples. In this Comment we derive the conditions, crucial for the existence of the observed behavior, and show that they explain the key features of the experiment analytically. 
Maxim Yu. Kharitonov and Mikhail V. Feigel'man