They won't. Wenger will vamoose when he really thinks things are on the way down.
The Arsenal 'way' in 5 easy steps:
1) Start the season strong, kid yourself that THIS year your players have matured.
2) Win a 'tough' game away from home (ideally somewhere cold and northern - north of Watford will do) to show how mentally tough your players are.
3) Get a few injuries, emphasise that your squad will cope.
4) Squad doesn't cope, but it's OK, because next year, your team will be mentally stronger.
5) Fail to address key weaknesses in team. Start the season strong and claim that this year, your team has what it takes.