So far I've made contact with 2 alien races in systems adjacent to Sol: the Funafuti Collective and the Haora Empire. Both have recently been sending ships into Sol.
While the Collective appeared to simply investigate Halley's Comet and leave peacefully, the Haora made a massive colonisation push towards Mars which is of course sovereign territory of the Terran Federation. After all warnings to stay clear of the inner solar system were ignored, the fighter wing escorting the closest ship (which was later discovered to be a commercial colony ship) was given permission to open fire. The ship proved to be unarmed and only lightly armoured despite being over 20,000 tons, and was quickly destroyed. Even in the face of such a threat however, the remaining 5 ships in the convoy continued on their course towards Mars. Ultimately, the Federation were forced to destroy the rest of the colony ships. Over the next couple weeks, dozens of identical colony ships flooded into Sol, all heading towards Mars. Time and time again, Federation fighters destroyed the alien ships before they could reach their destination. As of this moment there are around 50-60 wrecks of such colony ships drifting around Sol. The Federation are not completely merciless though, as any lifepods that survived the destruction of a ship were picked up and the survivors were given a small environmentally-controlled biodome on Earth in which to live, albeit under close guard.
Then, for almost 2 weeks, no further Haora ships entered Sol. At the end of that period however, Haora warships were detected transiting into Sol. There was no mistaking them for commercial ships; they were faster than any of the previous ships so far, and many emitted EM pulses which were detected by tracking stations on Earth - the signature of active sensors.
And so the first Interstellar War truly began.
