Shared ground
Jephthah’s speech is a defense of his earlier choices, not a full replay of the battle. He presents a timeline: (1) the Ammonite threat was severe, (2) he asked Ephraim for help, (3) they did not intervene, (4) he knowingly took a life-risk and attacked anyway, and (5) Yahweh granted the victory (Judges 12:2–3).
The text also assumes a tribal setting where help from another tribe is possible but not guaranteed. Jephthah’s main point is about timing and legitimacy: Ephraim is challenging him after the crisis has already been resolved.
Where interpretation differs
Some interpreters read Jephthah as mainly reporting facts: Ephraim truly failed to respond, and their later anger is unreasonable. Others think the speech may be self-serving: Jephthah is framing events to protect his honor and leadership, and the reality of “calling” Ephraim (how, when, and how clearly) may have been more complicated.
A related difference is how people read Jephthah’s final question (“why… this day?”). Some take it as accusing Ephraim of opportunism (they want credit or dominance only after victory). Others take it as pointing to a breakdown in communication or expectations between tribes.
Why the disagreement exists
The narrative before this (Judges 11) does not explicitly mention Jephthah calling Ephraim, so readers must decide how to weigh a claim that is only reported here. Also, key phrases can be read with different strengths: “called” could be a formal summons or an urgent appeal; “didn’t deliver/save me” could mean “you refused” or simply “you never showed up.”
What this passage clearly contributes
Explicitly in the text: Jephthah claims he sought Ephraim’s help, received none, took a calculated risk (“my life in my hand”), crossed over to fight Ammon, and credits Yahweh with handing Ammon over to him. He then challenges the legitimacy of Ephraim starting a fight “today,” after the victory.
Reasonable theological inference: the passage highlights how quickly internal rivalry can replace external unity, even when God-given success is acknowledged. It also shows a leader interpreting deliverance as both divine gift (“Yahweh delivered…”) and a basis for evaluating later disputes about honor, participation, and authority.