It works, too. You'll find yourself considering the decisions you have to make more fully. Beyond the act itself (should Sam Fishe♋r kill an innocent?), questions of trust (how will this affect my standing with the NSA?) and consequence (how m😼uch harder will this make my next mission?) become real factors that create real tension and relief - especially when people close to Sam hang in the balance.

That said, your decisions have a limited effect on the story itself. The between-chapter videos and expository montages that drive the story do change to reflect your actions in previous missions, but they'll always set up the next mission the ✤same way. There are also a couple of big "to kill or not to kill" moments that will affect which of the three endings you see, but that's about it by way of plot influence.