After the recent poll, it is clear that the people of eastern Ukraine want to be a part of russia again. Unless Ukrainian government agrees and lets them join Russia, it should be allowed for them to enter in order to help the community, otherwise they will be stuck in between a conflict.
What has been currently presented in the news and also the recent events that have taken place between the two countries of Russia and Ukraine. The events that have taken place would lead us to expect that indeed the country will try invade and will probably say it is trying to protect Russians.
I believe that Russia is getting ready to enter Eastern Ukraine, they have already increased the military presence along the border and everyone knows that Russia likes to challenge the USA and other western countries. Russia doesn't feel the need to have an approval of any other country, they have always been in its own world and the western countries need to find a different method of dealing with Russia as obviously sanctions and threats only made the situation worse.
In history, the Crimea was ruled by the Russian government and the former monarchy of Russia. They will want to get the country that they used to rule back. We already saw when they went to that army base and took over the army base by killing the military that was in power their.
Putin is no idiot. Just because you have military on standby does not mean that he will invade Eastern Ukraine. If anything, he is probably just going to wait for the East secede from the rest of the country. It's coming to a point where either you're on your own, you join the EU, or you join Russia. It wouldn't surprise me if nations such as Belarus in the next decade or two joins Russia. Putin may likely be in power up to 2024 (maximum term length). So he has time on his side to patiently wait for the surrounding nations to fall back onto Russia.