Not every kind of human attachment and love are the same.
While we all know that attachment of the selfish kind is an inadvisable form of attachment, the attachment to our loved ones, to ideals, etc. is a part of life. Without such attachment life can turn cold, indifferent and inhuman.
Indifference will lead to coldness, to remain unattached and distant. How can empathy and relations develop then?
Devotion or attachment to a spouse or partner, to a son or daughter, etc. is human. An attachment that is born of love and promotes love and growth is a positive high quality.
So there is a distinction between possessive attachment and attachment that gives way and fosters inner bonds between beings who love one another, are connected and concern for one another. They think and feel for one another in unison. Duality and unity, synthesis only achieved by sharing , communication and giving. The middle path, the razor's edge.
(Note: Even possessive love may lead sometimes into a free giving love, therefore we should not discard possessive love as utterly negative.)
Often people try to give love and send good intentions that are aimed at the “universal”. They try to encompass in their love and good intentions all beings and aim to be all embracing. This is good and fine, yet, our love can only find expression in personal relationships. The “universal” is often a concept that involves all and nothing at all. There is no real commitment or involvement. Nothing can grow and reach the universal if it is not started and lived in the personal level of relationships.
Mahayana Buddhism knew it well: It is better to accept risks, suffering and vulnerability than to live a loveless life. Loveless not only in the sense of not being loved by someone else, but by being incapable of expensing or even worst, of loving another human being. If we can not give, we are not really living, at least not fully.
Attachment or detachment can not be used as an attitude to avoid the implications that love has on a personal level. First and foremost with those around us, and then a growing love and concern for the universal. For what can not be done in singular personal relationships can not be achieve on a universal scale. At the end, there is nothing to fear, but the incapacity to relate to ourself and others.
A good exposition of these ideas is made by Anangarika Govinda in his book “ Buddhist Reflections (published by Samuel Weiser)