It is obvious that Mexico, under their new Presidente, is actively aiding and abetting the caravans and thus is complicit in the invasion of the US. In fact, the Mexicans aren't even trying to hide their actions.
As for any military action, dream on. President Trump hasn't even suspended one yankee dollar of foreign aid to Mexico, Honduras, or any other country.
This is a question, why hasn't the President directed the end to any US money going to Central American states and Mexico. He is President and he can tell the director of foreign ‘Do it right now and provide me evidence you did or you are fired.’ Why is this so tough. BHO engaged in these sorts of actions regularly.