aggravate,embitter,heighten,intensify,make worse.
augment,enhance,increase,magnify,

ALLIANCE.

Synonyms:

coalition,confederation,fusion,partnership,
compact,federation,league,union.
confederacy,

Alliance is in its most common use a connection formed by treaty between sovereign states as for mutual aid in war. Partnership is a mercantile word; alliance chiefly political or matrimonial. Coalition is oftenest used of political parties; fusion is now the more common word in this sense. In an alliance between nations there is no surrender of sovereignty, and no union except for a specified time and purpose. League and alliance are used with scarcely perceptible difference of meaning. In a confederacy or confederation there is an attempt to unite separate states in a general government without surrender of sovereignty. Union implies so much concession as to make the separate states substantially one. Federation is mainly a poetic and rhetorical word expressing something of the same thought, as in Tennyson's "federation of the world," Locksley Hall, l. 128. The United States is not a confederacy nor an alliance; the nation might be called a federation, but prefers to be styled a federal union.

Antonyms:

antagonism,disunion,enmity,schism,separation,
discord,divorce,hostility,secession,war.

Prepositions:

Alliance with a neighboring people; against the common enemy; for offense and defense; alliance of, between, or among nations.