Possible Clues:

• Vindication for a flower on part of the tree leads to internal analysis
• Formal defence of one's conduct
• Formal defence of American Assistant overseeing igloo reconstruction
• The cardinal wrote one for his life
• A game soldier taking arrowhead for self-defence
• Written defence of one's conduct
• Written justification
• Formal defense
• Written justification by American PA overseeing igloo building
• Mint in silver wrapping I ate at the outset as defence