question about alliances

from what i understand in the rules, alliances are not allowed in standard matches. i'm not exactly sure of the rules, but could someone clarify for me? also, attached is some live game text from game no. 245942 to help with the clarification.
note: i had oceania and asia at this point. when the truce occurred and both players attacked me, i was quickly defeated. so, is the above situation allowable or not?
thanks for your help.
2007-02-23 00:29:09 - endowdly: wow, i just got unbelieveably shafter on the dice. wow.
2007-02-23 03:06:45 - tallfella27: how can you say that immediately after taking over nine territories? maybe you attacked too much
2007-02-26 15:24:15 - Dapper Tom: Tallfella: I propose a truce as green is really powerful. I won't attack you at all for 3 rounds if you agree to the same (and I won't attack you on this go now either)
2007-02-26 16:18:08 - tallfella27: I am green ... how about a truce anyway?
2007-02-26 21:39:44 - Dapper Tom: Hey Tallfella27. Sorry, being a bit daft. Truce for 3 rounds (i.e. until end of round 12 )sounds good. DT
2007-02-26 22:38:05 - tallfella27: sounds good ...
2007-02-26 23:56:23 - endowdly: that sucks
2007-02-27 00:35:40 - Dapper Tom: By the way, Tallfella, I don't mind if you attack my troops on Ontario and Quebec so that you can take North America (that will balance out our continents).
2007-02-27 01:49:40 - tallfella27: figured as much
2007-02-27 02:56:44 - endowdly: yeah so i got screwed. thanks guys. have a good time
2007-02-27 03:00:58 - endowdly: i hate those f'ing dice
2007-02-27 15:09:19 - tallfella27: truce is over ...
2007-02-27 15:57:13 - endowdly: lame
2007-02-27 16:26:16 - Dapper Tom: OK - nice while it lasted. May the best man win (I assume from your name that your a bloke).
note: i had oceania and asia at this point. when the truce occurred and both players attacked me, i was quickly defeated. so, is the above situation allowable or not?
thanks for your help.