This study investigates the potential use of the argument-counterargument structure in English L2 essays written by Indonesian EFL learners. It examines whether L2 proficiency affects the use of opposing views in their essays, and measures whether there is a correlation between the use of the rhetorical structure and the participants' overall essay quality. In order to achieve this purpose, the study asks participants to write an English argumentative essay and measures their English L2 proficiency. The researcher also requests that the participants write in Indonesian (L1) and uses the data to measure whether there is consistency in terms of the use of the argument-counterargument structure in their L1 and L2 essays. The results show that the majority of the students developed a one-sided model of argumentation in their L1 and L2 essays by focusing only on how to state their main claim and providing relevant justification for it. The students' relatively low L2 proficiency was found to be one of the possible factors behind their inability to include other-side views in their essays. In addition, the participants' use of rhetorical features affected the overall quality of their essays. Pedagogical implications of these findings will be discussed.