Possible Clues:

• American ally within NATO, for example
• A familiar Frenchman in Unesco, maybe
• Eg, Nato, Sars
• SCUBA, for one
• LETS, perhaps, be intimate in the morning
• America protecting ally in NATO, for example
• Army chief initially on manoeuvres for NATO, maybe
• Eg, NATO or EMU
• NASA, e.g.
• Word formed from 1st letters of other words