My question is, can true wisdom ever be devoid of compassion?
Or would true wisdom by it's nature necessarily contain compassion?
In other words, is the risk of developing a cold, cruel wisdom a real possibility?
Yes but within Early Buddhism there is less of a chance since the very first training--which comes before the training in wisdom--includes loving-kindness meditation, as well as compassion, and mutual joy.
In Buddhism, Wisdom is seeing the Three Characteristics, seeing that our reality is impermanent and interconnected--not being confused into thinking that anything really exists on its own.
In my own experience, knowing this does not necessitate compassion, but it certain makes compassion almost automatic.
It is unusual to be wise (read: to see the interconnected non-self nature) about something and not compassionate as well. Usually it is because when one has wisdom
To explicate the word "compassion" further, in Buddhism, there are four of these very wise emotions, the Four Brahmaviharas: loving-kindness, compassion, mutual joy, equanimity.
These four qualities are interrelated with wisdom--especially the latter.
When someone says "compassion" they are usually talking about the Four Brahmaviharas.
One should read about or do these meditations to find out how closely tied together they are with wisdom.
Nonetheless, the two are not always synchronous and there do exist states of mind during the Stages of Insight where the one's wisdom and ability to see the Three Characteristics is high but one's compassion for oneself and others not so easily attained.
Basically, compassion/the Brahmaviharas often lend to greater wisdom, relative and absolute, but in my experience, wisdom only occasionally leads to compassion--especially because wisdom is missing the element of calm and peace.
It may also answer your question to think about The Five Faculties (wisdom, faith, energy, concentration, mindfulness). After learning what they are and having an idea how they inter-relate to each other it would be worth noting the following: no single factor is in its true form unless supported by the other. They are one cohesive organism... every organ is strengthened by the others. These five factors are recommended as evaluative gradients to be mindful of to enter into concentration.
The wisdom component has its opposite complement: faith. This is similar in energy to compassion in its unconditional love, acceptance, and understanding.
Thus, contemplate about those 5 Faculties. Instead of just Wisdom and Compassion, there may be more fruit of thinking of Wisdom, Faith, Concentration, Energy, and Mindfulness and how they power each other up and may even be Ultimately the same thing.
Also, another perspective:
Dualism is the modality through which our thinking mind operates and is able to master the world--but it is also the very trap that sets us apart from Awakening. That previous sentence is a very trite sentence in Buddhism but it is valid and true: sometimes we can use our distinction-creating mind where it is not correct. At the Ultimate level Compassion and Wisdom are the same thing. Knowing is Loving, Loving is Knowing.