There were 36 wars in the 20th century that started and ended before 1914.

Those wars had about 500,000 deaths.

http://www.war-memorial.net/wars_all.asp

    Chinese Govt vs Bai Lang (White Wolf) Rebels	1914 - 1914	 5,000	
    2nd Balkan War	1913 - 1913	 60,500	
    Kuomintang vs Chinese Army	1913 - 1913	 5,000	
    Moro Rebellion	1913 - 1913	 15,050	
    1st Balkan War	1912 - 1913	 82,000	[1]
    Paraguay Coups	1911 - 1912	 5,000	
    Italo-Turkish War	1911 - 1912	 20,000	
    First Sino-Tibetan War	1911 - 1912	 2,000	
    Cuba vs Partido Independiente de Color	1911 - 1911	 1,050	
    Chinese Revolution	1911 - 1911	 1,000	[2]
    Asir-Yemen Revolt	1910 - 1911	 9,000	
    French Conquest of Wadai Sultanate	1909 - 1911	 12,000	
    The second Rif War	1909 - 1910	 10,000	
    Portugese war against Dembos	1907 - 1910	 5,100	
    Ma al-’Aynayn’s Anti-Colonial Insurgency	1907 - 1910	 3,150	
    Korean guerilla war against Japanese occupation	1907 - 1910	 17,736	
    Iranian Constitution War	1908 - 1909	 1,100	
    Morocco unrest	1907 - 1908	 1,400	
    Romanian Peasant Revolt	1907 - 1907	 2,000	
    4th Central American war	1907 - 1907	 1,000	
    Dutch-Achinese War	1904 - 1907	 24,200	
    Sokoto and UK vs Mahdist Revolt	1906 - 1906	 2,080	
    Zulu Rebellion	1906 - 1906	 2,356	
    Third Central American war	1906 - 1906	 1,000	
    Russian Revolution 1905	1905 - 1906	 1,500	
    Maji Maji revolt	1905 - 1906	 8,840	
    Russo-Japanese war	1904 - 1905	 151,831	[1]
    Southwest African Revolt	1904 - 1905	 12,800	[1]
    Uruguay Civil War	1904 - 1904	 1,000	
    Second Yemen Rebellion	1904 - 1904	 30,000	
    Uprisings in Colonial Angola	1902 - 1904	 2,000	
    Ilinden Uprising	1903 - 1903	 6,330	
    The War of a Thousand Days	1899 - 1903	 100,000	
    Philippine insurrection	1899 - 1902	 20,500	
    Second Boer war	1899 - 1902	 30,800	
    The Boxer Rebellion	1900 - 1900	 3,003	
    Sino-Russian War	1900 - 1900	 4,000

EDIT: I'm on mobile. Sorry for the awful formating.