1762
u . s . officials say some intelligence indicates a red line may have been drawn around the capital with republican guard units ordered to use chemical weapons once u . s . and allied troops cross it .
 attack: use
Please tell me event type and its trigger word from given type options. Output format is "type: trigger".  Option: declare bankruptcy, transfer ownership, marry, die, phone write, arrest jail, convict, sue, transfer money, end organization, start organization, end position, merge organization, start position, transport, charge indict, elect, attack, injure, born, extradite, release parole, sentence, demonstrate, meet, trial hearing, divorce, nominate, fine, appeal, pardon, execute, acquit 
Text: {0} 
Answer:
 attack: use