Complex sentence: On 28 June, Brazil revoked all neutrality between all of the Allied and all of the Central Powers; although the country did not declare war, this move allowed Brazilian merchantmen to travel in Allied convoys.
Split into simpler sentences: On 28 June, Brazil revoked all neutrality between all of the Allied and all of the Central Powers. Although Brazil did not declare war, this move allowed Brazilian merchantmen to travel in Allied convoys.