Question: The Juniper Passion is set during which assaults against the Winter Line?

Context paragraphs:
13th Street station (SEPTA): 13th Street station (formerly 13th/Juniper Street station) is a SEPTA Market-Frankford Line and Subway-Surface Lines station in Philadelphia, Pennsylvania, under Market Street between 13th and Juniper Streets in Center City.  The station serves the Market–Frankford Line and as the terminus for all five routes of the Subway–Surface Trolley Lines.  Until 2011, it was named the 13th Street stop on the Market–Frankford Line and as the Juniper terminus for the Subway–Surface Trolleys.

Michael F. Williams: Michael F. Williams (born 1962, New Zealand) is a composer of contemporary classical music.  He has received commissions from many of New Zealand's major musical institutions such as the New Zealand Symphony Orchestra, NBR New Zealand Opera and Chamber Music New Zealand and his work is regularly broadcast on Radio New Zealand Concert.  A lecturer in composition at the University of Waikato, Williams has received recognition in the NZSO-SOUNZ Readings on three occasions and in the SOUNZ Contemporary Award in 2012 for his multimedia World War II opera, The Juniper Passion.

Battle of San Pietro Infine: The Battle of San Pietro Infine (commonly referred to as the "Battle of San Pietro") was a major engagement from 8–17 December 1943, in the Italian Campaign of World War II involving Allied forces attacking from the south against heavily fortified positions of the German "Winter Line" in and around the town of San Pietro Infine, just south of Monte Cassino about halfway between Naples and Rome.  The eventual Allied victory in the battle was crucial in the ultimate drive to the north to liberate Rome.  The battle is also remembered as the first in which the troops of the Royal Italian Army ("Regio Esercito") fought as co-belligerents of the Allies following the armistice with Italy.  The original town of San Pietro Infine was destroyed in the battle; the modern, rebuilt town of the same name is located a few hundred meters away .

Winter Line: The Winter Line was a series of German and Italian military fortifications in Italy, constructed during World War II by Organisation Todt and commanded by Albert Kesselring.  The series of 3 lines was designed to defend a western section of Italy, focused around the town of Monte Cassino, through which ran the important Highway 6 which led uninterrupted to Rome.  The primary Gustav Line ran across Italy from just north of where the Garigliano River flows into the Tyrrhenian Sea in the west, through the Apennine Mountains to the mouth of the Sangro River on the Adriatic coast in the east.  The two subsidiary lines, the Bernhardt Line and the Hitler Line ran much shorter distances from the Tyrrehnian sea to just North East of Cassino where they would merge into the Gustav Line.  Relative to the Gustav Line, the Hitler Line stood to the North-West and the Bernhardt Line to the South-East of the primary defenses.

Strongpoint: In military tactics, a strongpoint is a key point in a defensive fighting position which anchors the overall defense line.  Its primary requirement is that it should not be easily overrun or avoided.  A blocking position in good defensive terrain commanding the lines of communication, such as high ground, is preferred.  Examples from history include Thermopylae, where the ancient Greeks held back a much large Persian army, and Monte Cassino, which anchored the Winter Line in Italy in World War II.

Battle of Monte Cassino: The Battle of Monte Cassino (also known as the Battle for Rome and the Battle for Cassino) was a costly series of four assaults by the Allies against the Winter Line in Italy held by Axis forces during the Italian Campaign of World War II.  The intention was a breakthrough to Rome.

The Juniper Passion: The Juniper Passion is a 2011 opera by New Zealand composer Michael F. Williams to a libretto by John Davies.  The opera is set in 1944 during the World War II Battle of Monte Cassino, an Allied victory, but with a loss of life totalling approximately 105,000 deaths, including many New Zealand soldiers, over the series of battles.  "The Juniper Passion" is written in three acts, six principal roles and chorus and is scored for chamber orchestra with digital effects.  Performance is through dance with only minimal movement and interaction by the singing cast.  In place of traditional sets, the opera has a 3-D computer graphic set design by Sean Castle that recreates the Benedictine abbey at Cassino.  This is interspersed with images taken during the battle by Richard Ferguson Davies, father of librettist John Davies.

Battle of Anzio: The Battle of Anzio was a battle of the Italian Campaign of World War II that took place from January 22, 1944 (beginning with the Allied amphibious landing known as Operation "Shingle") to June 5, 1944 (ending with the capture of Rome).  The operation was opposed by German forces in the area of Anzio and Nettuno.  The operation was initially commanded by Major General John P. Lucas, of the U.S. Army, commanding U.S. VI Corps with the intention being to outflank German forces at the Winter Line and enable an attack on Rome.

Operation Diadem order of battle: Operation Diadem order of battle is a listing of the significant formations that were involved in the fighting on the Winter Line and at the Anzio bridgehead south of Rome during "Operation Diadem" in May - June 1944 which resulted in the Allied breakthrough at Cassino and the breakout at Anzio leading to the capture of Rome.

Moro River Campaign: The Moro River Campaign was an important battle of the Italian Campaign during the Second World War, fought between elements of the British Eighth Army and LXXVI Panzer Corps ("LXXVI Panzerkorps") of the German 10th Army ("10.  Armee").  Lasting from 4–26 December 1943, the campaign occurred primarily in the vicinity of the Moro River in eastern Italy.  The campaign was designed as part of an offensive launched by General Sir Harold Alexander's Allied 15th Army Group, with the intention of breaching the German Army's Winter Line defensive system and advancing to Pescara—and eventually Rome.

Supporting paragraphs: The Juniper Passion Battle of Monte Cassino
Answer: Battle of Monte Cassino