'RelatedManager' object is not iterable Django

Hey i have looked around through some simliar posts here on SO but havent found anything that has solved my problem. I have the following models,

from django.db import models

class Areas(models.Model):

    name =  models.CharField(max_length = 120)
    order_in_sidebar_network = models.IntegerField(blank=True, null=True)
    order_in_section_network = models.IntegerField(blank=True, null=True)


    def __unicode__ (self):
        return self.area_name

    class Meta:
        verbose_name_plural = "Areas"
        verbose_name = "Area"

class Countries(models.Model):
    name = models.CharField(max_length = 120, help_text = "The name of the country")
    area = models.ForeignKey(Areas, verbose_name = 'Area')

    def __unicode__ (self):
        return self.name

    class Meta:
        verbose_name_plural = "Countries"
        verbose_name = "Country"
        ordering = ['name']



class Offices(models.Model):
    country = models.ForeignKey(Countries, verbose_name = 'Country')
    name = models.CharField(max_length = 255, help_text = "The name of this office, IE London")
    main_office = models.BooleanField(default= False, help_text = "Is this office a key location?", verbose_name = "Key Location")
    address_1 = models.CharField(max_length = 255, null = True, blank = True)
    address_2 = models.CharField(max_length = 255, null = True, blank = True)
    address_3 = models.CharField(max_length = 255, null = True, blank = True)
    city = models.CharField(max_length = 255, null = True, blank = True)
    postcode = models.CharField(max_length = 20)
    tel = models.CharField(max_length = 30, null= True, blank = True, help_text = "Optional telephone contact number")
    mobile = models.CharField(max_length = 30, null= True, blank = True, help_text = "Optional mobile contact number")
    fax = models.CharField(max_length = 30, null= True, blank = True, help_text = "Optional fax contact number")
    data_1 = models.CharField(max_length = 255, null