Correct

宣战

/ xuānzhàn / 
Strokes

Definition

to declare war

Example

As a Verb

declare/proclaim war (on/against); dig/take up the hatchet

1
Xiàng
向
qīnlüèzhě
侵略者
xuānzhàn
宣战

declare war against the invaders

As a Verb

battle; fight a battle

2
Xiàng
向
fēidiǎn
非典
xuānzhàn
宣战

fight a battle against SARS

3
Xiàng
向
áizhèng
癌症
  
/
pínkùn
贫困
xuānzhàn
宣战

declare war on cancer/poverty