In YE 33, following a UOC-wide invasion by the NMX, the planet was attacked by sizeable NMX space and ground forces. The NMX quickly gained orbital superiority and landed several thousand mecha and supporting infantry on the planet of Tange IV, resulting in widespread confusion and fighting between the UOC defenders and the NMX. Intense street fighting occurred across the planet of Tange IV.
Three days after the beginning of the attack, the 4th AASP Fleet, reinforced with several dozen escorts and hundreds of transports, arrived in the system. The effort was codenamed “Operation Dynamo”. The Nepleslians swiftly beat off the NMX ships in orbit and began immediate evacuation of Tange's population. They were responsible for the evacuation of over 250,000 Jiyuuians from Tange.
Following the evacuation, most of the Jiyuuians rescued by 4th Fleet chose to take up Nepleslia's offer of asylum and integration into the Democratic Imperium.
In early July YE 33, the NMX invaded the Tange system with a small force of warships consisting of cruisers and destroyers. They quickly dispatched the space defenses in the system and began a swift, large-scale invasion of Tange IV. They had been in the system for less than two hours.
The military installations on Tange V and VI were attacked from orbit by NMX battlepods. Communications between these installations and the main command and control centers on Tange IV ceased at 2:13PM.
At roughly 2:04PM, the first NMX forces consisting of Ripper Power Armor and NMX Type 31A Light Infantry units landed in Misato City. Due to the extremely swift advance, many UOC civilians had yet to make it to the nearest shelters. Despite the best efforts of the veteran UOC Peacekeepers, the NMX slaughtered millions of civilians and infecting many more with the release of parasites. Millions more were left stranded in the streets when the shelters were sealed.
On Nepleslia Prime, news of the NMX invasion of the UOC had just become common knowledge. Nepleslian commanders first thought to make a counter-offensive, either in the region or in lightly defended area. However, those hopes were soon dashed when the news of the UOC's impending collapse came in. On orders from the Sky Marshall, plans for the evacuation of the UOC systems began in earnest.
Rear Admiral Dominic Valken was placed in charge of what he dubbed, “Operation Dynamo”. His first task was to find enough ships to transport the UOC personnel. Valken ordered the activation and crewing of hundreds of mothballed transports and the NSS Destiny, though most of them were skeleton crews augmented by numerous junker drones. With the transport fleet taking ship, Admiral Valken had to find a way to crew enough escorts with the limited personnel available for assignment.
Eventually, with great efforts, Admiral Valken managed to assemble what he considered “barely enough” to make a return trip into a single UOC system, so long as the NMX presence was minimal or non-existent. Just as this was about to be ready for deployment, Admiral Valken received orders to take over the 4th AASP Fleet from Admiral Heram J. Wazu. No reasons were disclosed, only that Admiral Valken was to roll the two operations into one concerted effort.
The Tange system was chosen as the primary objective with the Miyamae System as its secondary objective in the event that Tange prove to be impossible to evacuate. If both systems were unable to be evacuated for any reason or overrun by the NMX, Admiral Valken was to bring his ships home empty-handed.
Due to the small number of Marines in 4th Fleet, as many available squads were hastily attached from local assignments. The quality of these units ranged from freshly graduated Marines to grizzled old combat veterans. The equipment issued varied greatly as well, causing several headaches in terms of logistical preparation. Given the hurried nature of the operational planning and critical need for swift deployment, Admiral Valken was forced to accept the lack of homogeneity in his units.
The main plan was to secure orbit so as to land the Marines with the objective of gaining control of various space ports on Tange IV. Once in control, the Marines were to attempt to contact the UOC forces present and evacuate as many civilians from the sites as possible. In total, six space ports were chosen for their location near UOC population centers.
On the third day following the NMX invasion, the 4th AASP Fleet arrived in the Tange system, significantly increased in numbers by the temporary addition of transports and escorts.
Following a brief but bloody skirmish, the Nepleslian armada succeeded in forcing the withdrawal of the NMX invasion fleet. Six of the Oberon escorts were destroyed and many other ships were heavily damaged. Nonetheless, it cleared the way for the Nepleslian Marines to land and secure the six space ports from which they would evacuate as many personnel as possible.
As soon as the space ports were secured, Nepleslian transport ships began their descent into Tange, escorted by the rearmed FA4s of Green Squadron. NMX air assets were minimal but the presence of large scale mecha such as the NMX Ravager made the descent hazardous.
In orbit, 4th Fleet began transmitting its intent over open air radio channels in the hopes that surviving UOC forces would take heed. Green Squadron craft performed a quick pamphlet drop portions of Misato City before returning to its dual role of air superiority and ground attack.
Nepleslian Marines did not venture far from their locations, leaving the responsibility of safeguarding civilians en route to the UOC Peacekeepers. This was done because the Marines did not have enough personnel to hold a perimeter as well as provide escort to and from the space ports. The sudden arrival and activity at the space ports alerted the NMX ground forces already on site to the Nepleslians' presence.
Dozens of NMX units began converging on the space ports, threatening to overwhelm the Nepleslian and UOC defenders through sheer numbers. Within a couple hours, the Hizagari space port and its Nepleslian garrison had fallen, necessitating its closure as an evacuation site. An AIR2 squad sent to reinforce the Arame space port was ambushed and wiped out, save for a single survivor.
But after four hours of work, the NMX fleets returned in greater numbers, forcing Valken to end the evacuation. After a valiant rearguard effort by parts of the 4th Fleet escort, Valken took the fleet to the Virginia system and then to Nepleslia Prime where the UOC evacuees were processed for temporary housing and medical checks.
In total, 267,808 UOC civilians and Peacekeepers were evacuated from the planet. 68 Nepleslian sailors and 14 Nepleslian Marines were killed in action. It is not known how many living UOC civilians and Peacekeepers were still present on the planet when 4th Fleet had to abort its evacuation.