Attachment, affection and love denote the feeling which animates a person who is genuinely fond of someone or something.
Attachment and affection differ in that affection usually has for its object a sentient being, whereas that of attachment may be even an inanimate thing.
Attachment implies strong liking, devotion, or loyalty; affection, rather warmth and tenderness of sentiment.
Affection and love differ in that affection implies a feeling more settled and regulated, less intense or ardent, than love, which alone of the three may connote passion.
Thus to one's friends any one of the three terms may be applicable; to the members of one's own family, love or affection, but usually not attachment; to God, love (in the sense of reverent devotion), but not affection or attachment; to one's country, love, especially if ardent patriotism is implied, affection, if the emphasis is upon genuine but not blind devotion, attachment, if allegiance and loyalty are definitely connoted.