In the years leading up to World War I, the SPD remained ideologically radical in official principle, although many party officials tended to moderation in everyday politics. According to Roger Eatwell and Anthony Wright, the SPD became a party of reform, with social democracy representing "a party that strives after the socialist transformation of society by the means of democratic and economic reforms". They emphasise this development as central to understanding 20th-century social democracy, of which the SPD was a major influence. In the 1912 federal election, the SPD won 34.8% of votes and finally became the largest party in the Reichstag with 110 seats, although it was still excluded from government. Despite the Second International's agreement to oppose militarism, the SPD supported the German war effort - motivated, in no small part by opposition to, and fear of, Tsarist Russia - and adopted "Burgfriedenspolitik", refraining from calling strikes or criticising the government. Internal opposition to the policy grew throughout the war. Anti-war members were expelled in 1916 and 1917, leading to the formation of the Independent Social Democratic Party of Germany (USPD).