what martin said is true.
thou points you need to check
is your broker in the country of war? if no then you dont need to worry.
is your broker account in the currency of the warring country? if no then you dont need to worry
is your bank in your warring country broke? if yes then you must contact your broker to refund your money to another bank in which you open a new account (preferably outside of the warring country) then you have no problems.
good "stateless" banks provide visa credit cards for people with enough buffer on their account.
i can highly advice you the first pacific bank (hong kong) - account opening fees only aroumd 500$
and the pacific private bank (vanuatu) account opening fees around 300$
besides the usual suspects from caymen islands, isle of men, jersey etc etc (damn UK is a real tax heaven buttpirate country. isnt it)
both of these bank cooperate with the big brokers (even with most forex brokers- i got no clue why they operate with retail forex brokers and their tiny tiny clients. but i doubt they accept anything below $25k)
but be aware. i highly doubt any private bank will accept a client based in a crisis state if he doesnt have some good old buckies ($€¥) to wave around infront of their nose.