指代范围不同。war、warfare一般都译为“战争”，但warfare多是指某种战术或战争。warfare是不可数名词，war可数或不可数名词都可以，所以“一场战争”不可能说a warfare，只能说a war。

warfare的例句

In the history of coalitionwarfaresuch impasses have been common, and sometimes disastrous.

在联合作战的历史中，这种相持不下的局面是很普通的，往往也是灾难性的。

This does not mean the abandonment of vital strategic points, which can be defended in positional warfare AS long AS profitable.

这并不是说要放弃战略要冲，只要认为有利，战略要冲还是应该用阵地战来保卫的。

By the late 4th century BC, armed deck soldiers had become so important in naval warfare that it was superseded by heavier ships.

在公元前4世纪末期，装甲兵在海战中很重要，因此该船被更重的船取代。

war的例句

The hope of a short war went glimmering.

战争无望在短期内结束。

A series of provocations led up to the border war.

一系列的挑衅事件导致了边境战争的发生。

The army was disbanded when the war came to an end.

战争结束时，军队即被解散。