How was Ronald Reagan effective with his variety of sentence length? Who was he appealing to$?$ What type of sentences are the last three sentences?

There is one sign the Soviets can make that would be unmistakable, that would advance dramatically the cause of freedom and peace. General Secretary Gorbachev, if you seek peace, if you seek prosperity for the Soviet Union and Eastern Europe, if you seek liberalization: Come here to his gate! Mr$.$ Gorbachev, open this gate! Mr$.$ Gorbachev, tear down this wall!

$-$Ronald Regan, standing at Berlin's Brandenburg Gate before the wall that still separated Western and Soviet sectors in the city, July $12,1987$