

I mean, you can argue some semantics about “peaceful”.
What it is undeniable is that it prevented global powers from going directly to total war, resulting in a much diminished number of casualties (both soldiers and civilians) compared to the World Wars. Nothing since then, even if we summed up all the wars going on around the world at any given moment, rival the unthinkable numbers of dead who piled up those conflicts, nor - if I can speculate a bit - would they have rivaled another worldwide industrialized conflict.
But.
Does that actually mean the world is “more peaceful”?
One can argue that the undeniable reality that you are much less likely to be killed in a war between nations today means “Yes.” One can also argue that peace should not be measured by cold mathematics: That the continued existence of smaller-scale conflicts around the world, internal conflicts within countries, or deaths from non-national conflicts such as the ongoing gun violence epidemic in the US or deaths caused by polluting megacorporations mean it has not gotten “more peaceful”; the risks have just changed.
I suppose it depends on how you are analyzing all of this, in the end.
You’re already asking good questions, which means you’re doing a lot better than many of the people who adopt without thinking. You’re also looking for an adult cat, which means you aren’t going to have to deal with a kitten’s destructive exploratory phase (although, fair warning, adult cats can still be destructive if you don’t prepare properly).
One thing I would say is that you should consider two versus one cats. Some cats don’t handle being alone for a long time well and can become unhappy, while others prefer not having feline company and would be just fine alone for ~48 hours. A good shelter or adoption agency may be able to tell you whether a cat prefers company or solitary.
Like some other commenters, I would strongly suggest going to local shelters and discussing with them. They should entirely understand if you aren’t able to adopt immediately and be able to discuss particulars with you.