This is not correct. Starting in May 2014, Ukrainian nazi battalions were bombing and shelling civilian populations in Donetsk and Luhansk. The OSCE documented the slaughterm, noting that Ukraine was even using fixed wing aircraft to bomb civilian population centers in the Donbas. Putin came under immediate pressure from the Russian population (who watched the bombings every night on their TV) and their representatives in the Duma to take immediate action to intervene to protect the ethnic Russians livinfg in the eastern provinces. This was the whole reason for the Minsk Accords!!

Had there not been a genocide, there would have not been a need for the Minsk Accords, which provided protection and autonomy for the ethnic Russian population.

Your fear of a Russian invasion of Latvia is ungrounded. The documents you cite say:

"Strategy documents prepared by the Russian president’s office show Moscow’s plans for maintaining influence in Lithuania, Latvia, and Estonia. These include funding pro-Russian NGOs, efforts to keep Russian language in schools and oppose demolitions of Soviet monuments."

Those measures are a long way from military action.

As long as the Latvians do not start to actively attack, segregate, discriminate or otherwise persecute the Russian population of Latvia, Putin will not be pressured to intervene.