 The Combined Chiefs of Staff, however, were concerned that should Operation Torch precipitate Spain to abandon neutrality and join the Axis, the Straits of Gibraltar could be closed cutting the entire Allied force's lines of communication.They therefore chose the Casablanca option as the less risky since the forces in Algeria and Tunisia could be supplied overland from Casablanca (albeit with considerable difficulty) in the event of closure of the straits.Marshall's opposition to Torch delayed the landings by almost a month, and his opposition to landings in Algeria led British military leaders to question his strategic ability; the Royal Navy controlled the Strait of Gibraltar, and Spain was unlikely to intervene as Franco was hedging his bets.