Identify the prepositional phrase. the headlines announced a truce between the two countries. the headlines announced between the two countries a truce between announced a truce
A prepositional phrase begins with a preposition and end with a noun, pronoun, gerund, or clause, the object of the preposition.
preposition - between
modifier - the two
noun - countries
A prepositional phrase needs to contain a preposition, in this case it would be "between". As well it needs to modify the sentence and it should mention the object of the sentence. So "between the two countries" is correct.
between the two countries, hope it helps