intervene
verb (used without object)
to come between disputing people, groups, etc.; intercede; mediate.
Used to describe an ongoing action or state that is currently taking place in the immediate present.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Since circumstances have set me in their path, I am intervening in their defence and for their safety.
From The Eight Strokes of the Clock by Maurice Leblanc