The initiative of creating a European Army actually is in the air of the European Union.
Both French president Emmanuel Macron and German chancellor Angela Merkel declared this month that they support the need to create a joint European army. By the way these two countries are the strongest EU member states from economic and political points of view. Their words are not just "air shaking" but the subject to think it over.
France is the only remaining nuclear power in the EU once Britain leaves the organization -- and Germany -- its major economic power. Both countries make up about 40 % of the industrial and technological base in Western and Central Europe, as well as 40 % of the EU overall capabilities and of combined defence budgets.
The main reason why European leaders voiced the initiative now can be considered from two different points of view. From one hand this can be the indicator of European fears of Russia, China and even the US military activities. According to Macron, "an EU army is needed to "protect ourselves" with respect to these states."
On the other hand such initiative can be used by France and Germany to stop the US from weakening Europe and promoting its interests in the region. Donald Trump reacted to the statement by tweeting: "Emmanuel Macron suggests building its own army to protect Europe against the U.S., China and Russia. But it was Germany in World Wars One & Two -- How did that work out for France? They were starting to learn German in Paris before the U.S. came along. Pay for NATO or not!" Thus, he tied closely the idea of a European Army to his demand to increase defence spending to NATO.
At the same time the initiative of strengthening the European collective defence capabilities not only irritates the US but scares many EU countries as well.
As for the Baltic States, they have not formed their official opinion yet. The matter is the Baltics are "between two fires." The EU membership gives them good political positions in Europe where they try to gain respect and influence. But the US remains their main financial donor and security guarantee at the moment. They can't sacrifice relationships with Washington for the sake of ephemeral European Army. It means that there is a greater likelihood that Latvia, Lithuania and Estonia will softly reject the idea. It is not necessary to expect strong opposition to Germany and France. But they surely will do their best to postpone decision making.
After all the initiative could become an "apple of discord" in the EU and split the organization in two sides making the organization even weaker than now.