When Lafayette entered Virginia, Cornwallis complied with Clinton's orders and withdrew to Yorktown, where he constructed strong defenses and awaited evacuation. An agreement by the Spanish navy to defend the French West Indies allowed Admiral de Grasse to relocate to the Atlantic seaboard, a move Arbuthnot did not anticipate. This provided Lafayette naval support, while the failure of previous combined operations at Newport and Savannah meant their co-ordination was planned more carefully. Despite repeated urging from his subordinates, Cornwallis made no attempt to engage Lafayette before he could establish siege lines. Even worse, expecting to be withdrawn within a few days he abandoned the outer defenses, which were promptly occupied by the besiegers and hastened British defeat.