Okay let say Italy to Argentina? One phase to bring troops there then attack right there? I'm just making sure I got it clearly.
well let me go to the deep
If you're transporting troops to a battlefield (example France, as the US) then it'll take you one turn to take your across the Atlantic and one to make them land in the designated area.
Like this;
1-5) build 5 infantries.
6) ship all units across the Atlantic to France.
7) units land in France.
But if for example the French coast is occupied by the Communists and you need to give vital reinforcement then it'll be like.
1-5) build 5 infantries.
6) shipping all units across the Atlantic to France.
7) the units attack the Port of Dunkirk, they need a seven to firmly occupy the port (here you roll the dices).
If you get 7+ then with the loss of one infantry you can take over the port and land the remaining infantries,since you're the US you have 10 turns so I'm writing all example turns
8) build infantry
9) shipping the infantry to Dunkirk
10) the infantry division lands at Dunkirk. I now have x troops in the USA and five infantries in France.
But if you're sending backup to the French then there is a limit, 5 infantries or 3 tanks, once these units have been delivered to your ally they will be now in your ally's command (though in previous wars I was India and I sent best75 a lot of backup forces which were nearly 20 infantries, those infantries were in my as well as in Best's command so they were quite much like an international army commanded by two different countries, India and the ROC (best was ROC)), so I suggest you keep either these units in your command or either give your ally full control over them or either both get to use these units.
Which in case would be like
1-5) build five infantries
6) transport all infantries to (insert ally country)
7) the units have landed in (insert allied country here to whom back up is given) and can now be controlled by both me and (insert ally to whom the backup is given).
Whew! That was big! Hope you understand now