Paul Treisman : But Western restrictions on investment and trade with Crimea could amplify the effect . Only a few days are left to discuss the Crimea breakaway . He says if Crimea votes to join Russia , that will greatly strengthen Putin 's position . Russia and EU need to apply economic pressure , make the case for a ` ` no '' vote , he says . Putin : Crimea must see the choice is between prosperity and stagnation .
Paul Treisman : Only a few days are left to discuss the Crimea breakaway . He says if Crimea votes to join Russia , that will greatly strengthen Putin 's position . Russia and EU need to apply economic pressure , make the case for a ` ` no '' vote , he says . Putin : Crimea must see the choice is between prosperity and stagnation .