I live in a community that does not have an eruv.
The neighborhood is very very dangerous with lots of crime, assaults, robberies, etc.
Is there any leniency in carrying, somehow pepper spray for example, in the case of protection, i.e., like hatzalah and soldiers? Thank you in advance.
It is hard to answer your question because I don’t know the extent of the circumstances in your community, therefore you would have to speak to a Rov that lives in your area, and an assess your situation correctly. It is noteworthy though, that there is a difference between a lay person that is going outside on shabbos voluntarily, and a hatzalah member who needs to go outside or a soldier who has to be present in order to actively protect the area.
Best Wishes and have a good and safe Shabbos: