The Systems Alliance-Vies War of 2190 (shorter, more descriptive name pending approval by political experts and the public) was a conflict between the Systems Alliance and the Republic of Vies, taking place in the Attican Traverse.
The conflict was preceded by a lesser war between the republics of Vies and Caleston over colony ownership disputes between the two. The ignition point of the Vies-Caleston war was the palladium-rich world of Avakk III, which Vies had laid claim to and Caleston had occupied. Viesian forces made an undeclared attack on Calestoni forces stationed on the planet, which prompted Caleston's declaration of war in retaliation.
The Systems Alliance became involved in the conflict, as Caleston is a major supplier of element zero to them and they host a SAN naval base in the region as well. As a result, the Systems Alliance sent observers to Avakk III for Caleston's counter-attack, but Viesians took them as hostages. Vies threatened their two Systems Alliance marines with execution, if the SA did not withdraw their support to Caleston. The Alliance conducted a rescue mission instead that succeeded in rescuing the captives but provoked the situation into an open war between the two states.
The actual conflict itself ended up lasting two years. Avakk III saw bitter ground warfare both in open and urban terrain. Systems Alliance's forces in the theater also included Turian Hierarchy detachment and local allied PMC. The Viesi used nerve gas, provided by their backers in the Confederacy, but it did not provide the desired force multiplier to their war efforts. Come 2192, the Systems Alliance was victorious, and dictated terms of surrender to the besieged Viesi republic.
The Initial Conflict: Caleston and Vies go to war.
Disregarded Wars: The prologue for the Systems Alliance involvement.
Down to Business: Also known as "CDN starts a war". The situation becomes more complicated.
I Hate You All: CDN prepares itself for the fallout. Much recrimination is involved.
The Blame Passes Around: Dano and Mekan point fingers.
Debrief Redux: The Special Tasks Group deals with the aftermath.
Vies Accuses: The outcome of the CDN adventure makes the news. The Viesi are very annoyed.
First Bullet: Those involved in the incident reflect.
Breaking News: The new war officially breaks out, and the Alliance mobilises.
I Made A Sign: Iel'Verret says "no" to war.
Please Donate: A contrite Liria wants to raise money for Nat to have a cloned replacement arm - but should she bother, since Nat (the trolls gleefully insist) is going to die in a war now, and it's all Mekan's fault!
The Giant's Fist: The Systems Alliance off to war.
Where Is Mekan?: Lying low, it seems.
News Update: The fighting continues. CDN natters about it.
Dead of the Night: Insurgents attack.
Consultation with the Devil: Mekan makes plans.
Back in Black: Mekan and crew head back to the Caleston Rift.
Violence of Action: Mekan and co in the thick of it.
Behaviour Unobserved: A new year, and Nat's still on Avakk III.
Handover: The Alliance begins the process of handing Avakk III over to Caleston control.
Okay, it was me: Dano admits he might have started a war.
Alliance Used Cerberus Forces?: Having lost the war, Vies and its backers make some rather overblown claims regarding poor behaviour on the part of the winners.