Passage of
Lines Passage of lines is an operation in which one unit passes through the lines of another unit that is stationary. A passage of lines is generally conducted when one unit’s mission requires a movement through terrain occupied by another unit. Examples of passage of lines operations are
· Security operations
· Counterattacks
· Retrograde operations When a unit moving
· Forward towards the enemy passes through a stationary unit, it is a forward passage
· Away from the enemy passes through a stationary unit, it is a rearward passage
Whenever possible, avoid a passage of lines because units are particularly vulnerable.
Relief in Place A relief in place is an operation in which one unit replaces another unit and assumes the relieved unit’s responsibilities. The primary purpose of a relief in place operation is to maintain the combat effectiveness of committed units.
Relief in place is a difficult operation to execute because it requires both control and flexibility. To simplify the relief and maintain operational security, certain equipment and supplies may be transferred between the two units.
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MCI Course 8015A 3-63 Study Unit 3, Lesson 3
Other Defensive Operations,
ContinuedRetrograde
Operations Retrograde operations are an organized movement away from the enemy.
Whether forced or voluntary, a higher commander approves the rearward movement.
Retrograde operations are
· Conducted to harass, exhaust, disrupt, or delay the enemy to
· Gain time
· Avoid combat under unfavorable conditions
· Draw the enemy into an unfavorable position
· Used to
· Reposition forces
· Shorten lines of communications
· Permit the use of forces elsewhere
· Are difficult: Delays and withdrawals are inherently risky
Types of Retrograde Operations
The three types of retrograde operations are
· Delays: Slow the enemy, cause enemy casualties, and stop enemy without becoming decisively engaged
· Withdrawals: Unit disengages from the enemy and repositions for some other mission. Withdrawals can be done while under pressure and not under pressure. In a withdrawal under pressure, the unit disengages and moves to the rear while in contact with the enemy.
· Retirements: Operations in which a force that is not engaged with the enemy moves to the rear in an organized manner. Retirements may
· Follow withdrawals
· Begin before contact with the enemy
MCI Course 8015A 3-64 Study Unit 3, Lesson 3 Exercise
Lesson 3 Exercise
Estimated
Study Time 20 minutes
Directions Complete the following items. Check your answers against the correct answers at the end of this lesson. If you have any questions, refer to the reference page listed for each item.
Item 1 Which of the following statements is correct concerning the information that should be included in the attachment paragraph of a defensive operations order?
a. The attachment paragraph should include information on when supporting units are going to link up with your unit.
b. The attachment paragraph should include information on which attachments are going to be with the main effort.
c. The attachment paragraph should include information on the exact times when supporting units are going to attach and detach to your unit.
d. The attachment paragraph should include information on the location of all the attachments supporting every unit in the defense.
Item 2 To answer the following question below, select
· a if only 1, 2, and 3 are correct
· b if only 1, 3, and 4 are correct
· c if only 1 and 3 are correct
· d if all four are correct
Which of the following are the missions that units can assume while conducting defensive operations?
1. Prevent the enemy from moving in a specific direction 2. Protect and hold a piece of terrain
3. Cause the enemy casualties and repel their attack
4. Cause the enemy casualties and break up their formations
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MCI Course 8015A 3-65 Study Unit 3, Lesson 3 Exercise
Lesson 3 Exercise,
ContinuedItem 3 Which of the following are details that must be addressed in the coordinating instructions?
a. Establish routes to and from resupply points b. Percentage alert during hours of darkness c. Signal to commence and cease fire
d. Designation of a force to act as the reserve
Item 4 Which of the following are phases for conducting the defense?
a. Reconnaissance, location of the enemy, fighting the defense, reorganization, actions on enemy contact
b. Reconnaissance, location of the enemy, occupation of the defense, emplacing of weapons systems, movement into the defense
c. Preparation of the defense, reorganization, movement into the defense, employment of the reserve, actions on enemy contact
d. Fighting the defense, location of the enemy, preparation for combat, counterattack, occupation of the defense
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MCI Course 8015A 3-66 Study Unit 3, Lesson 3 Exercise
Lesson 3 Exercise,
ContinuedDirections for Items 5 Through 7
To answer the following questions below, select
· a if only 1, 2, and 3 are correct
· b if only 1, 3, and 4 are correct
· c if only 1 and 3 are correct
· d if all four are correct
Item 5 Which of the following are actions that must occur during the reconnaissance phase of the defense?
1. The commander halts the unit short of the position, establishes local security, and assembles his leaders for a reconnaissance.
2. The unit leader should take all the key personnel with him for the
reconnaissance and not plan for enemy activity while the reconnaissance is gone.
3. The unit leader should confirm enemy avenues of approach, dead space in front of positions, and the location of SPs/LPs.
4. Unit leaders make final preparations for movement, complete and issue their defensive orders, and conduct final inspections and rehearsals.
Item 6 Which of the following are principles of movement while occupying the defense?
1. Units should maintain all-around security to include air sentries.
2. Formations and techniques used should be based on the commander’s estimate of the situation.
3. Units should move along covered and concealed routes.
4. Unit leaders should enforce camouflage, noise, and light discipline.
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MCI Course 8015A 3-67 Study Unit 3, Lesson 3 Exercise
Lesson 3 Exercise,
ContinuedItem 7 Which of the following are considerations for occupying a defensive area?
1. Reconnaissance routes to and from alternate and supplementary positions.
2. Weapons, positions, and obstacles should be looked at from the enemy’s point of view.
3. The defensive fire plan sketch should be completed upon occupying the defense and delivered to the next higher commander.
4. Sectors of fire should be confirmed, and interlocking fires and dead space should be checked.
Item 8 Fill in the blanks as indicated below.
Unit leaders must ensure the following actions are accomplished while fighting the defense:
· Initiate direct and indirect fires as planned.
· ___________________________________________
· Communicate with adjacent units.
· Report to the company commander.
· ___________________________________________
Item 9 Which of the following best describes the purpose of the reserve?
a. The primary means of breaking the enemy’s attack or denying him the ability to regain the initiative.
b. To preserve the commander’s flexibility.
c. To establish local security and respond to enemy penetrations.
d. To assist with other missions such as resupply, patrolling, and the construction of obstacles.
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MCI Course 8015A 3-68 Study Unit 3, Lesson 3 Exercise
Lesson 3 Exercise,
ContinuedItems 10
Through 15 Matching: In the space provided, place the letter of the type of primary mission from column 2 that best matches the definition in column 1. The answers in column 2 may be used only once.
Column 1 Definition
Column 2
Type of Primary Mission ___ 10. The initial position of the
reserve should be located near the most likely point of enemy penetration or near the main effort ___ 11. The rapid execution of a
hasty counterattack may be the key to the defensive battle
___ 12. The reserve is positioned where it can fire into unoccupied areas between forward units and on their flanks and rear
___ 13. The reserve can be used to blunt the enemy
penetration and fix the enemy force in place ___ 14. The reserve can be
committed to bolster forward units that could achieve success but require more combat power
___ 15. The reserve prepares supplementary positions to secure the unit’s flanks and rear
a. Reinforce the main battle area b. Add depth
c. Block or contain penetrations d. Protect flanks and rear areas e. Hasty counterattacks
f. Support a forward element by fire
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MCI Course 8015A 3-69 Study Unit 3, Lesson 3 Exercise
Lesson 3 Exercise,
Continued
Item 16 A counterattack is the primary means of a. preserving the commander’s flexibility.
b. breaking the enemy’s attack or denying him the ability to regain the initiative.
c. maintaining the combat effectiveness of committed units.
d. disrupting or delaying the enemy’s attack while conducting an organized movement from the enemy.
Item 17 List the two types of counterattacks.
______________________________________________________________
______________________________________________________________
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MCI Course 8015A 3-70 Study Unit 3, Lesson 3 Exercise
Lesson 3 Exercise,
ContinuedItems 18
Through 21 Matching: In the space provided, place the letter of the type of primary mission from column 2 that best matches the definition in column 1. The answers in column 2 may be used only once.
Column 1 Definition
Column 2
Type of Primary Mission ___ 18. An operation where a unit
that is already assigned a primary defense mission, though under extreme conditions, is further assigned to a reserve force ___ 19. An operation which one
unit passes through the lines of another unit that is stationary
___ 20. An operation in which one unit replaces another unit and assumes the relieved unit’s responsibilities ___ 21. An operation that calls for
the organized movement away from the enemy
a. Passage of lines b. Retrograde operation c. Least-engaged unit d. Relief in place
MCI Course 8015A 3-71 Study Unit 3, Lesson 3 Exercise
Lesson 3 Exercise Solutions
Correct
Answers The table below provides the correct answers to the exercise items. If you have any questions, refer to the reference page listed for each item.
Item Number Answer Reference Page
1 c 3-48
MCI Course 8015A 3-72 Study Unit 3, Lesson 3 Exercise
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MCI Course 8015A 4-1 Study Unit 4