An organisation jointly run by the Trump campaign and the RNC has tried to get donations with a Support the Troops poster campaign.
Given Trump’s known disdain for US troops it is perhaps appropriate that the troops in the picture are Russian.
Occam's Razor seems appropriate here.
Does anyone really believe that Trump even knows how to use a computer, let alone personally tasks himself with making his own ads? And do you really think that he or his team would intentionally use silhouetted Russian troops and Russian jets? You've got to love the conspiracies that insinuate "coded messages" or "hidden in plain sight," as if only they will secretly know and no one else can figure it out.
Its far more likely due to ignorance that they came across a picture that was actually a Russian recruiting ad and no one in Trump's administration bothered to cross-reference to see if it even was American made. Guarantee whoever made it has been fired, because mistakes are not allowed in Trump's cabinet.... ever. That is to say, he's allowed to make all the mistakes in the world and then blame them on other people.
"Reason obeys itself; and ignorance submits to whatever is dictated to it" -- Thomas Paine