Possible Clues:

• Evasive language
• Deliberately ambiguous language, and an apt description of 18-, 26-, and 46-Across
• Distrust involving the French with occasionally warlike ambiguous utterings
• Evasive communication, and a hint to 18-, 27-, 36- and 45-Across
• Gobbledygook
• Baloney
• Gibberish!