Actually China was involved in WW1. Chinese Infantry on the way to Siberia Chinese Translators Chinese working in Munitions factory.
From Wikipedia China participated in World War I from 1917 to 1918 in an alliance with the Entente Powers. China never sent troops overseas, however, 140,000 Chinese labourers (as a part of the British Army, the Chinese Labour Corps) served for both British and French forces before the end of the war.
Despite long treaty with Great Britain, Portugal stayed out of WWI. They stayed out of WWII also, sort of, they leased bases to the USA and Britain in Azores Islands.