Metta is seen as the natural result of a flowering Buddhist practice. Wikipedia has a statement that is worth quoting in full that “The cultivation of loving-kindness (mettā bhāvanā) is a popular form of meditation in Buddhism. In the Theravadin Buddhist tradition, this practice begins with the meditator cultivating loving-kindness towards themselves,^[7] then one’s loved ones, friends, teachers, strangers, enemies, and finally towards all sentient beings. In the Tibetan Buddhist tradition, this practice is associated with tonglen (cf.), whereby one breathes out (“sends”) happiness and breathes in (“receives”) suffering.^[8] Tibetan Buddhists also practice contemplation of the Brahmavihāras, also called the four immeasurables, which is sometimes called ‘compassion meditation’^[9]”

However it should be noted that friendliness in itself is not the highest value in Buddhism (Conze, Buddhist Thought in India) nor does it appear in the Noble Eightfold Path, the Five Cardinal Virtues, the Six Perfections, or the Seven Limbs of Enlightenment. Nor can it be said that friendship with Muslims is essential to the success of Buddhism. Just as Nirvana is found through wisdom beyond metta, skillfully extinguishing the delusions and illusions in others can have the same enlightening effect.

The Pali word for delusions that characterize our dark age is avija.  Avija is translated as ’ignorance,’ nescience, unknowing; “and synonymous with delusion (moha, s. mūla), it is the primary root of all evil and suffering in the world, veiling man’s mental eyes and preventing him from seeing the true nature of things. It is the delusion tricking beings by making life appear to them as permanent, happy, substantial and beautiful and preventing them from seeing that everything in reality is impermanent, liable to suffering, void of ‘I’ and ‘mine’, and basically impure (s. vipallāsa). Ignorance is defined as ‘not knowing the four truths, namely, suffering, its origin, its cessation, and the way to its cessation’ (S. XII, 4).

All beings who live in this ignorance are capable of the most regrettable kamma. This is the opposite of the Dhamma, adhamma: unrighteous, injustice, wrong conduct, and immorality. To act in ways antithetical to the dhamma or those upholding it is against natural law and criminal in nature. This fundamental lack of education on the Four Noble Truths is the most pressing matter of the 21st century should be the most serious issue of our time.  The delusions lead them to impure kamma and suffering upon themselves and their loved ones is the most obvious contribution of the world’s fastest growing religion. It is of utmost importance that this situation be rectified so that the metta of Buddha and the wisdom of Dhamma can shed light on this darkness and bring peace to them or the whole world will have to continue to suffer the consequences.

Surely not all of them will be mindful enough of the benefits of the Buddha’s teaching but those who’s eyes can be opened should be given every opportunity to join the Order and return to their countries to bring the flower of Dhamma to their nation of origin.

There are those who incorporate Dhamma into the religion of Christianity, finding comfort in Christ as the savior and mindfulness to access the inner reaches of virtue. There is no reason why a Muslim cannot find the wisdom of Mohammad quicker with a mind stilled in meditation. Along with protecting the faith from unacceptable proselytizing and forced conversions, I think this is the best approach for showing Muslims the metta of Buddhism. Ignorance is not limited to any race or creed of which any wisdom is notably lost among the wider Buddhist community of “friends, relatives, colleagues, neighbors, and paper citizens” who choose to celebrate holidays of ignorance bathed in oceans of blood.