Like all marvelous adventure stories, Richard Reeves's ''A Passage to Peshawar'' is teeming with contrasts in landscape, incident, and innuendo, all of which are tamed by the keen eye and vivid insights of the narrator. In this case, it is Mr. Reeves who brings order to an otherwise chaotic profusion, or at the very least reduces it to an understandable progression of random occurrences. This is no small achievement, given that the focus of his attention is the infinitely complex kaleidoscopic nation of Pakistan.
This devoutly Islamic country, which descends in an arc from the rugged mountains of the Hindu Kush to the tropical Arabian Sea shoreline, is as diverse an amalgam of cultures and peoples as can be found in Asia. Willed into being in 1947 by the determination of Muslim separatists and the deliberations of British cartographers, Pakistan is populated by dozens of tribes and races speaking a welter of Indian and Arabic-influenced languages. The sole unifying force, and indeed the very reason for the nation's existence, is the faith of Pakistan's 90 million citizens in the word and the teaching of the Koran.
The partition of the Indian subcontinent into Hindu-dominated India and the Muslim enclaves of West and East Pakistan (the latter became the independent nation of Bangladesh after a bloody civil war in 1971), in no way inaugurated the bitter conflicts: Pakistani against Indian, Sikh against Hindu, Assamese against Bengalese, Sindhi against Punjabi, and Muslim against Hindu - that continue to consume the passions and energies of the region. A succession of conquering armies, beginning with Aryan tribal warriors in 1500 BC, passed through the Khyber Pass, strewing the Indian subcontinent with the parings of their civilizations. Culture was heaped upon culture, language upon language, sect upon sect, to create the ever-shifting ensemble of rivalries, alliances, customs, and anomalies that enlivens Mr. Reeves's extended essay on Pakistan.
In ''A Passage to Peshawar,'' Pakistan emerges as a nation struggling against immense odds to remain, in Reeves's words, ''promodern but not necessarily pro-Western.'' Conspicuous for many years solely because of its dire poverty and puritanical Islam, Pakistan was refashioned in the wake of the Soviet invasion of neighboring Afghanistan into what the United States government accurately calls ''a frontline state.'' Pakistan's borders became America's outer defensive perimeter, and the nation itself a hastily-fortified barricade standing in the way of the Soviet Union's tactical advance on the warm water Asian ports that are considered a prime strategic objective of the military planners in the Kremlin.
Overnight, a trickle of US aid became a torrent, and a nation whose social and economic development had been arrested some 500 years earlier, was suddenly hoisted by billions of dollars in foreign aid to the brink of modernization. Cars, farm machinery, and television antennas began appearing in primitive mud-walled villages, arousing the concern and suspicions of Pakistan's powerful Muslim clergy.
The mullahs, fearful that Western goods and ideals were having a corrosive effect on traditional Islamic society, repeatedly denounced changes in the social and economic order brought on by the infusion of overseas aid. As a result, progress has been sporadic. But it seems a certainty, according to Reeves, that the lure of the 20th century, and with it the opportunity to shed custom for the household conveniences and public precepts of the West, will eventually win out in Pakistan.
Such a triumph would likely not come without great social upheaval. Islamization - the process of safeguarding the primary role of Muslim teaching in Pakistani society - has a powerful and ardent champion in President Zia Al-Haq. One of America's closest Asian allies, Zia is portrayed in contrasing hues, as an amiable yet ruthless despot, who has managed to stay in power both by inveigling the Muslim clergy, and agreeing to shoulder much of America's geopolitical burden in South Asia.
Pakistan's current preoccupation with the situation in Afghanistan has diverted attention for the moment from the country's smoldering political problems. Now in its eighth year under martial law, Pakistan has yet to resolve the potentially explosive conflicts that have loomed large since independence. Secessionist tribes in the north, newly armed with sophisticated weapons intended for the Afghan resistance fighters, have staked out a place beyond the laws and the control of the Pakistani government. Women, still manacled by Islamic law to lives of rigorous labor and social exclusion, await their deliverance from second-class status. And the nation's political leaders and journalists, held in check by Zia's martial law edicts, are now quietly clamoring for democratic reform.
A fragile truce holds in Pakistan at present, but the future appears increasingly uncertain. Pakistan, Reeves writes, ''is a time bomb . . . a country that might be shattered by explosions if its internal pressures are not vented into the building of a truly modern state.''
The value of ''A Passage to Peshawar'' rests largely with the author's ability to communicate, in language both precise and evocative, the tugs of modernity and tradition on the turbid soul of this populous nation. Reeves, one of America's ablest political reporters, probes the many incongruities of Pakistan, questioning, examining, weighing with the conscience of a self-professed ''innocent abroad,'' the traumas of the society lurching toward an uncertain destiny.
Wandering from the palm-fringed coast, where swarms of day laborers armed only with hand tools, dismantle mothballed American tankers and British naval vessels into piles of scrap metal, the bazaars along the Afghan border where Western military hardware is bartered for newly refined heroin bound for American and European cities, Reeves unravels the tangled skeins that bind Pakistan to the West.
In so doing, he casts sobering light on issues as diverse and momentous as the global spread of the English language, the frequent failure of the US government to lend its support abroad to the democratic ideals it upholds at home, and the predicament of nations cast as pawns in the game of strategic one-upmanship played by the superpowers.
Richard Reeves aims quite high in ''A Passage to Peshawar,'' scrutinizing both the particular pressures hastening change in Pakistan, and the more wide-ranging problems faced by nations whose strategic importance far exceeds their level of development. Yet, he succeeds masterfully. ''A Passage to Peshawar'' is a virtuoso performance by a first-rate journalist at the peak of his reportorial and interpretive powers.