> California has not declared war on Texas, but the states are engaged in a "redistricting war," a political struggle over drawing new congressional maps. This "war" is a symbolic conflict between the states' differing political parties and aims to gain an advantage in the U.S. House of Representatives, with California attempting to counterbalance Texas's Republican-drawn map.
If numerous publications are referring to your country having a war, then it might as well be ok for a lay-person to use the word.