The talisman features a divine being called Jatukam Ramathep, unknown in Buddhist or Hindu sacred literature. He seems to be the invention of a confused imagination, and most intelligent commentators condemn this new cult as indicating a corruption of both Buddhist morality and Thai animistic spirituality.

In order to understand the problem, we need to get the god's name right:

Jatukam Ramathep is the Thai pronunciation of the Pali Catugamaramadeva, meaning God Rama of the Four Villages. This is near nonsense as no ancient literature, Buddhist or Hindu, connects Rama to "Four Villages". Thus the name seems to have been created out of thin air.

However, the talisman is connected in the popular imagination to the Great Stupa of Nakhon Si Thammarat. According to respectable tradition preserved in an ancient document (see Wyatt, DK, "The Crystal Sands: The Chronicles of Nagara Sri Dharmmaraja", Cornell) the relics enshrined in the Great Stupa there came from Sri Lanka and the stupa was established with the assistance of traders from Sri Lanka, where Buddhism has always been protected by Hindu gods.

(The evidence is in the Mahavamsa and in folk religion to this day.)
Here is the evidence as far as I have been able to trace it from credible physical and documentary sources:

At the Great Stupa at Nakhon Si Thammarat, the stairs leading up to the circumambulatory terminate in a narrow stage with four images of gods. To the extreme left and right are two gods in brick and plaster with no attributes. However inscribed stone plaques (in apparently old lettering) announce that they are Lord Khattugama and Lord Ramadeva.

The door in the centre consists of two wooden leaves each carved with a deity in high relief. One is obviously Vishnu with his disc and conch, but he also holds a bow, indicating that he is the Rama incarnation. The other deity has four visible faces and so has been identified as Brahma, but he holds weapons (unlike Brahma who holds sacrificial implements).

If one counts the invisible faces (at the back of the relief) one gets six. The six faces and the weapons indicate the god Skanda (known in Sri Lanka as Kataragama) who has six faces and holds all weapons as Commander of the Heavenly Forces.

A 16th century Pali chronicle (see Penth, H Jinakalamali Index, Pali Text Soc, 1994) tells the following tale: the King of Sukhothai had heard of the fame of a Buddha image in Sri Lanka and he desired to acquire it. He sent an emissary to the king of Nakhon Si Thammarat, who reported that Sri Lanka was invincible as it was protected by four gods, namely Khattugama, Rama, Lakkhana and Sumana.

In Sri Lanka, today, popular tradition claims that the island is protected by four great deities, among whom are Kataragama (Khattugama in Pali) and Rama under the tittle Upulvan (the Blue God or Vishnu) but as he holds a bow we must suppose he is the Rama incarnation.

All this information may seem confusing to those unfamiliar with Hindu-Buddhist mythology and iconography, but from this respectable evidence we may construct a credible history.

 In the late 12th century Sri Lankan Theravada Buddhism became established in mainland Southeast Asia together with its relics, footprints, Bodhi trees, texts and protective deities. These were most faithfully recorded and remembered at Nakhon Si Thammarat. However in modern times, tradition has been forgotten. People lack knowledge of the texts to which I have referred. As a result they have confused the two guardian deities, Khattugama and Ramadeva, and conflated and corrupted their names, producing Jatukam Ramathep, a single deity without a historical background.

But who can blame the Thais?

I am reminded of a tale told (I think) by Evelyn Waugh. In Italy he once visited an obscure church that housed a splendid old woodcarving of St George on horseback killing the dragon. It was festooned with scraps of paper bearing prayers for wealth, health and success.

Waugh remonstrated with the parish priest about this gross idolatry. The priest ruefully agreed and added that when the cultural authorities removed St George for restoration, leaving the horse, his parishioners wanted to attach their petitions to its tail and mane. "My flock don't worship St George," said the priest, "they worship the horse!"

In like manner, it seems, many Thai Buddhists have forgotten the Buddha, his liberating teachings and the relics of his person, and instead devote themselves to a protective deity, and a spurious one at that.

Several distinguished Thai scholars have proposed that the Jatukam Ramathep phenomenon indicates a failure of Buddhism. I would prefer to avoid this conclusion as religions do not fail unless they become fossilised and obsolete (like classical paganism). Rather, societies fail to remember and live up to the admirable principles of their religions.

Indeed societies tend to pervert and demean their inherited wisdom.
In the case of the Jatukam Ramathep talisman here in Thailand, we have a society that counts greed and gain as the highest good, and an educational system that fails to provide access to Asian cultures. Nor does it make available to the public our most important historical texts.

If many Thais had read the relevant parts of the chronicles that I have quoted, then a nonsense deity like Jatukam Ramathep would never have been conceived.