CREATE TABLE table_203_653 (id NUMBER, "rank" NUMBER, "nation" CLOB, "gold" NUMBER, "silver" NUMBER, "bronze" NUMBER, "total" NUMBER)

how many more silver medals did the united states win compared to russia ?
SELECT (SELECT "silver" FROM table_203_653 WHERE "nation" = 'united states') - (SELECT "silver" FROM table_203_653 WHERE "nation" = 'russia')
SELECT (SELECT "silver" FROM "table_203_653" WHERE "nation" = 'united states') - (SELECT "silver" FROM "table_203_653" WHERE "nation" = 'russia')