def create_sns_topic(self, region):
        """Creates an SNS topic if needed. Returns the ARN if the created SNS topic

        Args:
            region (str): Region name

        Returns:
            `str`
        """
        sns = self.session.client('sns', region_name=region)

        self.log.info('Creating SNS topic for {}/{}'.format(self.account, region))
        # Create the topic
        res = sns.create_topic(Name=self.topic_name)
        arn = res['TopicArn']

        # Allow CloudTrail to publish messages with a policy update
        tmpl = get_template('cloudtrail_sns_policy.json')
        policy = tmpl.render(region=region, account_id=self.account.account_number, topic_name=self.topic_name)
        sns.set_topic_attributes(TopicArn=arn, AttributeName='Policy', AttributeValue=policy)

        auditlog(
            event='cloudtrail.create_sns_topic',
            actor=self.ns,
            data={
                'account': self.account.account_name,
                'region': region
            }
        )

        return arn
Creates an SNS topic if needed. Returns the ARN if the created SNS topic

        Args:
            region (str): Region name

        Returns:
            `str`