Identifying only specific words in a string

[GilbyScarChest]

Thanks for your help j.crater!

eventually what ended up working was this:

action = input("> ")
while True:
    if "fire" in action:
        print('You attack the alien ship!')
        break
    elif "attack" in action:
        print('You attack the alien ship!')
        break
    elif "shields" in action:
        print('You raise your shields!')
        break
    elif "defense" in action:
        print('You raise your shields!')
        break
    elif "hail" in action:
        print('You try to hail the alien ship!')
        break
    elif "communicate" in action:
        print('You try to hail the alien ship!')
        break
    else:
        print("Unknown action, try again.\n")
        action = input("> ")

There's probably a simpler way to do it, but this is the only way I could figure out right now.