Two consecutive sentences that begin with in
Solution 1:
In agreement I would be tempted to replace obvious duplication.
In your second sentence this can be easily remedied.
"In response to the current geopolitical crises plaguing the Middle East, specifically the Syrian Civil War, the war in Afghanistan, and instability in Iraq, the countries of Western Europe have experienced a substantial influx of refugees. During 2015 over a million migrants crossed into Europe seeking asylum, a number unprecedented in recent history."
Alternately Throughout etc.