A classic flank attack: Operation Desert Storm 1991
Flank attack - going around the side of the enemy instead of taking him head on is one of the most basic of manoeuvres. The ultimate goal is encirclement - sealing off and destroying the enemy.
In the modern theatre of battle where casualties run in hand in hand with the political will and stamina to continue combat, flank attack is ideal since it allows the commander to appear where the enemy least expect you to. The idea is not to hit the enemy head on but hit him in the side where he might be weak. If a formation comes from the front towards 100 men, all 100 can shoot at it, but if it comes from the side and if the defence line is only 3 deep, then only 3 can shoot at the incoming formation. Hence it can literally roll down the flank and crush the defender 3 at a time.
One of the classic flanking manoeuvres to take place was operation Desert Storm in 1991 where the allied coalition were pitted against Saddam's forces in Kuwait.
Norman Schwarzkopf - the supreme commander of the allied forces - at first prepares a head on assault from Saudi Arabia into Kuwait to drive the Iraqis out. But his battle planners urged him to reconsider pointing out the open flank to the west to exploit it. Intelligence also suggested that Saddam had a massive well equipped army dug into defensive positions all along the Kuwaiti border. Further to add such a head on assault with the 4th largest army of the world at the time was just the amount of casualties Schwarzkopf wanted to avoid with the Vietnam war syndrome firmly at the back of his mind.
To avoid hitting the well entrenched Iraqis head on, he and his battle planners decided that the main thrust would be toward Saddam's western flank 150 miles deep inside Iraq. With this in mind he begins his force build up in such a way that the build up would lead the Iraqis to believe the main thrust would be from South of the Kuwaiti border. Reports were deliberately leaked to the media to deceive the Iraqis that Schwarzkopf's Rules of Engagement (ROE) limited him to fight only within Kuwait and not in Iraq itself. Further as part of the concealment ops in November 1990 "Exercise Imminent Thunder" - a major amphibious assault landing exercise - by the Marine Expeditionary Force (MEF) is conducted South of the border. Naval units bombard the Kuwaiti coast and mine sweeping takes place. As further concealment, a base/FARP just 25 miles South of the Kuwaiti border is built. An ammo dump at Gravel Plains adjacent to the Kuwaiti border is also stationed. This made it easier to hide the main heavy attack units - the US 7th core and British armoured 1st division - in the desert West of the perceived main thrust. Like the fake radio messages to convince the Germans that an army existed in Kent in England before the D-day landings deception experts flood the air waves with with radio to convince Saddam that key units are still in original start positions along the Kuwaiti border. Furthermore trucks are driven to start positions in the East as a decoy while the real logistics for the main thrust move at night camouflaging themselves at day covering their tracks in the open desert.
During the final approach to D-day Schwarzkopf began his air campaign. Under this air cover Schwarzkopf moved his 7th core 150 miles west and 18th airborne core west to the 7th core. Then he launches his ground attack. First the southern assault backed by a faint amphibious assault on the Kuwaiti border. Meanwhile the 18th swept across Saddam's flank in the far west and cut off Iraqi supply lines. Then the tanks of 7th core and the British penetrated the Iraqi defences west of the Kuwaiti border conducting the "Hail Mary Pass" to trap Iraqis in Kuwait in one giant pincer movement.
While initiating a frontal assault from Kuwait pinning Iraqi forces in Kuwait and luring in more reinforcement into Kuwait, his flank attack will prevent reinforcement (after Iraqi reinforcements are in Kuwait), seal off escape routes, encircle them and destroy Saddam's army once and for all. Timing on giving the green light for the flank attack was crucial. As turned out, his frontal attack which was part of the concealment, was too successful and drove Iraqis out of Kuwait too quickly that his flank attack did not have enough time to completely seal off their escape. The success of the flanking manoeuvre meant that Saddam who earlier promised the "mother of all battles" was forced to perform the "mother of all retreats" as then Secretary of Defence Dick Cheyney elegantly put in.
The Sri Lankan example:
Coming onto the Sri Lankan theatre a classic flank attack was the liberation of VAKARAI (Viharaya) and subsequently the entire four-six sector comprising VAKARAI, KATHIRAVELI and VERUGAL.
After the successful completion of the SAMPOOR campaign, the Tamil Tigers were pushed South of the Verugal river.
Unlike Schwarzkopf who enjoyed a free open Western flank through the Iraqi desert the 23 Division commanders did NOT have a clear flank to exploit. The tiger defences were up to 3 lines deep South of the PANICHCHANKERNI bridge. Hence the initial battle plan was to create a flank involving the thin neck of land protruding East of the four-six sector mainland - that is the narrow stretch of land running up to CHALLITIVU bordering the Upparu lagoon.
On 16th of January 2007 (D-day) troops broke out from KADJUWATTA and by 18th January succeeded in breaking the second line of defence and by the same day evening the 3rd line of defence as South of PANICHCHANKERNI falls to the troops. With these rapid gains in hand 23 division builds up troops, artillery and armour South of the PANICHCHANKERNI bridge hinting that an imminent thrust was about to take place across the bridge. This was further strengthened by heavy volumes of artillery/MBRL fire towards the North bank defences of the Tamil Tigers and engineering units' persistent attempts to diffuse the explosives set along the bridge under the cover of artillery fire.
With this heavy build up of a superior force on the Southern bank, what the Tamil Tigers failed to realise was the fact that 23 division had created a flank East of their defences with the capture of the 3 defence lines they held a few days ago at PANICHCHANKERNI. The flanking attack spear headed by the Special forces commence across the narrow UPPARU lagoon backed by Special infantry and captured the VAKARAI town and hospital by 19th January 2007 (D+3). This caught the Tamil Tigers who were awaiting the main thrust from South unawares. The main thrust was so successful that the Tamil Tigers had no time to muster any counter attack and were in full retreat towards the TRICONAMDU jungles West of VAKARAI and THOPPIGALA. The rapid retreat of the Tamil Tigers who had fortified positions caught the battle planners by surprise, that troops (7GW, 6VIR) converging in to close the gap at TRICONAMADU failed to do so in time. Had the guerillas offered resistance and then retreated along the same jungle terrain, this may have given troops ample time to position themselves to intercept the fleeing guerilla cadres.
This VAKARAI battle also highlights the success of the transition of attritional guerilla warfare to a full blown conventional one. For nearly three months since October 2006, 23 division backed by Special forces conducted a series of raiding operations laying the groundwork for the final assault. The timing of the transition was crucial in this instance. The importance of the timing of the transition from guerilla warfare to a conventional one was amply demonstrated on 6th October 2006 when troops broke out from KADJUWATTA with the same four-six sector as their objective. The conventional tactics of the operation failed giving the Tamil Tiger media bread and butter that lasted for weeks.
As long as modern warfare presents with a well entrenched enemy, a battle planner will always consider to build up his force, conceal the main thrust, attack from the flank and finally encircle his enemy minimising his own casualties for public opinion will not allow for a nation's troops be thrown head on against a well entrenched enemy.