There will be roadblocks with controls. Some kind of identification system among the military (Think codenames like in Band of Brothers, where they all use "Thunder!" and the response "Flash!" during D-Day but a little more sophisticated these days).
And generally people talking to each other. It is easy to spot a different accent, someone looking like they are lost. Ever tried finding your way in a city like Kyiv without a map? And better don't let anybody catch you constantly looking at one/your phone while you are supposed to be a local.
Don't forget everybody is very, very attentive right now. People just going around without an apparent goal? Standing in small groups without a plan of what to do? Weird way of of greeting? All those things can get you caught.
Especially once the fighting in urban environments has been going on for a day or two small groups of soldiers tend to settle in. They guard the same street/bridge/etc. for hours upon hours (and days upon days). Lots of time to get used to the usual coming and going. And in turn it is very obvious when something unusual happens.
Just sit in a caffee for a day and watch people. Even after only one hours you have a pretty good grasp of the crowd and you start spotting different kinds of people. Just one look and you see if they are a student going to study (Bored). Or waiting for a date (Nervous). Or on the way to work (Exhausted).
And while considering all that (And tons more) remember a saboteur has to fool hundreds of people during hundreds of small interactions during one day for days/weeks on end. He only has to slip up once to get caught.
There will be roadblocks with controls. Some kind of identification system among the military (Think codenames like in Band of Brothers, where they all use "Thunder!" and the response "Flash!" during D-Day but a little more sophisticated these days).
And generally people talking to each other. It is easy to spot a different accent, someone looking like they are lost. Ever tried finding your way in a city like Kyiv without a map? And better don't let anybody catch you constantly looking at one/your phone while you are supposed to be a local.
Don't forget everybody is very, very attentive right now. People just going around without an apparent goal? Standing in small groups without a plan of what to do? Weird way of of greeting? All those things can get you caught.
Especially once the fighting in urban environments has been going on for a day or two small groups of soldiers tend to settle in. They guard the same street/bridge/etc. for hours upon hours (and days upon days). Lots of time to get used to the usual coming and going. And in turn it is very obvious when something unusual happens.
Just sit in a caffee for a day and watch people. Even after only one hours you have a pretty good grasp of the crowd and you start spotting different kinds of people. Just one look and you see if they are a student going to study (Bored). Or waiting for a date (Nervous). Or on the way to work (Exhausted).
And while considering all that (And tons more) remember a saboteur has to fool hundreds of people during hundreds of small interactions during one day for days/weeks on end. He only has to slip up once to get caught.