ISLAMABAD, Pakistan — For an idea of what unconditional love might look like on the geopolitical stage, look no further than Pakistan’s relationship with China.

As Islamabad prepares to welcome Chinese Prime Minister Wen Jiabao and some 250 Chinese businessmen for a three-day visit, local officials are waxing lyrical about their “all-weather friend.”

“We share each other’s joys and sorrows and have a complete identity of views on all issues,” said Pakistan Prime Minister Yousuf Raza Gilani. “I am sure that all our people will display their love and affection for their Chinese brothers and sisters.”

Pakistan President Asif Ali Zardari and Gilani have made numerous trips to China in the more than two years they’ve been in office, but visits by their Chinese counterparts to Pakistan have been more sparse.

(Read about Wen's charm offensive in India this week.)

The two neighbors plan to sign a raft of strategic and commercial agreements over the weekend. Wen will address Pakistan’s parliament — a rare privilege for foreign dignitaries — and officials from both countries are set to inaugurate the Pakistan-China Friendship Center, a massive cultural center located on the outskirts of the capital. In advance of the visit, Pakistan has declared 2011 the “Year of Pakistan-China Friendship.”

One thing the recent WikiLeaks disclosures made clear is that Pakistan’s circle of friends is limited. The United States’ assessment of Pakistan’s government as weak and corrupt was a surprise to no one, but Saudi King Abdullah’s description of Zardari as a “rotten head” and an impediment to the country’s progress came as a shock for many Pakistanis. By the same token, concerns expressed in diplomatic cables by the British government over Pakistan’s ability to secure its nuclear arsenal were to be expected, but similar worries by the Russians were not.

More slights from foreign governments came last week when both French President Nicolas Sarkozy and a German official criticized Pakistan for not doing enough to combat terrorism.

In this context, the renewed support of “Pakistan’s true and most reliable friend” — as Pakistan’s foreign affairs ministry calls China — is viewed here as crucial.

“Politically it’s significant because it comes at a time when Western powers — especially France and Germany — are building pressure on Pakistan to dismantle the so-called terror infrastructure on its soil,” said Naveen Hussain, national editor of the Express Tribune, a Karachi-based daily. “It seems as if Pakistan is isolated in the international community so words of reassurance from Prime Minister Wen are going to be very important.”

The relationship between the two countries is a time-tested one. Pakistan was one of the first countries to recognize the People’s Republic of China 60 years ago, and Islamabad has sided with Beijing ever since — including when it skipped the recent Nobel Peace Prize award ceremony for Chinese dissident Liu Xiaobo out of solidarity with China.

Hussain said the relationship grew “out of geographical proximity and mutual antipathy toward India.”

While India is considered a strategic rival by China, it is Pakistan’s perennial enemy with several wars and numerous skirmishes taking place between the two neighbors since partition of British India in 1947. Still today, even with the Afghan conflict encroaching on Pakistan’s tribal areas, India remains at the core of Islamabad’s foreign and military policy.

China’s investments in Pakistan have focused on infrastructure, from the famed Karakoram Highway that links China’s western region with Islamabad through some of Pakistan’s highest mountain ranges to the Gwadar port, a deep-sea harbor that offers convenient access to the Gulf’s oil supplies.

But China’s most controversial contribution has been its assistance to Pakistan’s nuclear program. China agreed this year to build two nuclear reactors in Pakistan. The commitment comes after the United States inked a nuclear energy deal with India in 2008 and refused to sign a similar agreement with Pakistan.

China’s involvement in Pakistan has not been without complications. In recent years, several Chinese workers have been kidnapped or killed by insurgent groups, which had the Chinese government “seriously concerned,” said Andrew Small, a Chinese foreign policy expert at the German Marshall Fund of the United States.

“The scale of China’s investment would be significantly higher if these incidents had not taken place,” he said.

Bilateral trade between China and Pakistan hovers around $7 billion a year. A five-year plan to boost annual trade to $15 billion is expected to be signed during Wen’s visit. The balance is largely in China’s favor, however, with imports from China six times larger than exports. Gilani said earlier this month that the issue should be addressed by increasing access to the Chinese market for Pakistani goods.

“On the economic side, China is getting more than Pakistan, clearly,” Small said.

By funding very visible projects and avoiding interference in Pakistan’s national affairs, China has been able to maintain a very positive image among the country’s general population. This is in sharp contrast to the United States, which remains deeply unpopular in Pakistan despite spending more than twice as much as China to help those affected by this summer’s floods.

Hussain lamented that China had not done more to stabilize democracy in Pakistan, but he said there was little room for altruism in China’s foreign policy.

“Whatever China is doing, it’s doing it in its own interest,” he said.