If you mean "istanbul agreements" in this agreement russia wanted ukraine to surrender and for example have limited troops, like one houndred thousands. so, that wasn't "agreements" and no one forced ukraine to continue war. 
this is very strange logic, russia invaded ukraine, ukraine wanted to defend but you blaming ukraine and someone to have the right to defend themselves. why don't you just say russia should get out of ukraine and that's it, no war. 

 And you conveniently forget the history of this. 1990 "NATO not one inch east"- James Baker, 2 Minsk peace treaties ignored by the west "we just used Minsk to buy time to arm Ukraine"- Merkel and Holland's admitting this, a coup by the west in Ukraine in 2014(no democracy), suspension of Ukraine voting and time limit on the presidency. 

You get the pattern ? 

 - Is Ukraine a member of NATO?
-  "we just used Minsk to buy time to arm Ukraine" - why then after two month of invasion Ukraine run out of artillery shells and why Ukraine still need weapons?
- "coup by the west in Ukraine in 2014" - If it was coup by the west - what was the reason for that?