Kinngrimm,
I will let Sauce reply on his official stance on the issue, but I will offer our reasoning for attacking.
Last night my guys tracked Manwe as he headed, rather apparently, towards Yruma. When I issued the order to attack, Manwe's circle was literally on top of the graphical image of Yruma on the map, and still appeared (according to my guys, I am out of view range) to be headed straight at the castle. With 300 troops unarmed and 700 crates we knew that was all goods, and did not want to risk a massive loss to Yruma's S&D at this time.
If his path had taken him farther from Yruma we would not have attacked, but without seeing his travel path it really appeared he was headed to Yruma.
Also, Remnant started Strat 4 with an open trade policy, but like most, it has changed to Closed with invite only.
** These new holdings in the north were added to the above list once we attained them, about a week ago or more.
NA Border Policy Thread -->
http://forum.meleegaming.com/diplomacy/strat-4-na-border-policy-list/I will leave the rest to Sauce, just wanted to explain our actions in this case.