With the national election approaching, Indian Prime Minister Narendra Modi's focus is squarely on domestic politics. After holding a secure grip on power for nearly five years, the governing Bharatiya Janata Party (BJP) faces a tough election fight following defeats in three key state-level polls in December.

Foreign affairs are understandably low on the election agenda. But after the vote, India's new government -- whether led by Modi or not -- will have to consider urgently the foreign-policy challenges, above all an ascendant China's muscular revisionism.

For too long, New Delhi has taken a cautious and reactive approach. But with Beijing spreading its influence deep into India's backyard, New Delhi needs to reverse its eroding regional clout.

A dynamic diplomacy needs strong, bipartisan policies. With India's fractious politics, building bipartisanship has long been tough in the world's largest democracy.

The danger now is that the election will likely see Modi's government lose its commanding majority in the Parliament's lower house and be replaced either by a weaker BJP-led administration or an opposition coalition of 20 or more groups supported by the Congress Party. Either way, foreign policy would be crimped.

Pragmatism, zeal and showmanship have been trademarks of Modi's foreign policy. Early on in his term, he unleashed Modi-mania among Indian diaspora audiences by taking the stage like a rock star at several places, including New York's storied Madison Square Garden.

A penchant for diplomatic surprises, however, has got him into trouble. For example, during a 2015 visit to Paris, Modi pulled a rabbit out of a hat by announcing an on-the-spot decision to buy 36 French Rafale fighter-jets. In the run-up to the election, the opposition has claimed that, behind that decision, there is a scandal involving inflated pricing and cronyism.

Modi made an on-the-spot decision to buy 36 French Rafale fighter-jets during a visit to Paris in 2015.   © Reuters

Modi has helped shape a nondoctrinaire foreign-policy vision. India, a founder leader of the nonaligned movement, now makes little mention of nonalignment. Shorn of ideology, Indian foreign policy has sought to revitalize the country's economic and military security, while avoiding having to overtly choose one power over another as a dominant partner.

However, in practice, closer cooperation with the United States has been Modi's signature foreign-policy initiative. India is now a "major defense partner" of the U.S., with which it holds more military exercises than with any other country. The U.S. has also emerged as India's largest arms supplier. The Cold War-era India-Russia camaraderie has been replaced by India-U. S. bonhomie.

India, however, relies on Russian spare parts for its Russian-made military hardware. More importantly, Russia has transferred to India offensive weapons that the U.S. does not export, such as an aircraft carrier. So ties to Moscow remain important.

India is also seeking to shield from U.S. pressures its cooperation with Tehran. Iran remains an important oil supplier to energy-poor India and is the route for a transportation corridor India is building to Afghanistan that bypasses New Delhi's arch-enemy Pakistan.

Although India has secured provisional waivers from American retaliation, the new U.S. sanctions against Russia and Iran have accentuated India's challenge in balancing its relationships.

Meanwhile, the recent "agreement in principle" that U.S. President Donald Trump's administration has reached with the Afghan Taliban, including promising an American military pullout within 18 months, is helping to renew the salience of Iran and Russia in India's Afghanistan policy. If the Pakistan-backed Taliban were to recapture power in Kabul, the relevance of these ties would redouble.

But, despite seeking to exit Afghanistan, the U.S. has become more vital to India's broader foreign-policy interests, especially in relation to China. Modi has worked to deepen India's cooperation with the U.S., Japan and the other Indo-Pacific powers that share Indian concerns about China's territorial and maritime revisionism.

But vexed by the Trump administration's unpredictability, Modi has also sought to mend ties with China, or at least stop them from deteriorating further. At an "informal" summit ten months ago in Wuhan, Modi and Chinese President Xi Jinping agreed to "reset" relations.

For Xi, however, Wuhan has served as a cover to kill two birds with one stone. While encouraging Modi's overtures to help instill greater Indian caution to openly challenge China, Xi has embarked on a major military buildup along the Himalayan border with India. The buildup has included deploying new offensive weapons and advertising live-fire combat exercises. Chinese encroachments in India's maritime backyard have also increased.

Meanwhile, Chinese exports have flooded India, with Beijing more than doubling its bilateral trade surplus, on Modi's watch, to over $66 billion a year. This trade surplus is more than 50% larger than India's defense spending, underscoring how India unwittingly is underwriting China's hostile politics.

India is holding its election after recent polls in most other countries in southern Asia. Since late 2017, elections have brought pro-China communists to power in Nepal and a military-backed party to office in Pakistan, while voters have booted out a quasi-dictator in the Maldives, elected a new government in Bhutan, and, in Bangladesh, retained a prime minister who has turned the country into one of the world's fastest-growing economies. Recently, Sri Lanka's Supreme Court forced the country's president to roll back a coup after he unconstitutionally dismissed the prime minister and called fresh parliamentary polls.

The next Indian government's most urgent foreign-policy problems relate to the country's neighborhood, not least a deepening strategic nexus between China and Pakistan -- a dangerous combination of an aggressive neighbor and an ascendant superpower. Both these nuclear-armed allies stake claims to swaths of Indian territory.

When Modi took office, many expected him to reinvigorate foreign policy at a time when the yawning power gap between India and China had widened. But, despite considerable Indian efforts, China's influence in India's backyard has grown, even in countries long symbiotically tied to India, including Nepal, Sri Lanka and the Maldives.

However, the most recent developments in Bangladesh, Sri Lanka and the Maldives, by bolstering or bringing to power pro-India leaders, have aided Indian interests, even as communist-ruled Nepal has tilted toward China.

Dealing with an aggressive China or complex regional-security challenges demands a decisive leadership that takes a long-term view and does not confound tactics with strategy. But such leadership is unlikely to emerge from the forthcoming election.

To be sure, India has been imbibing greater realism as its quixotic founding philosophy centered on nonviolence assumes a largely rhetorical meaning. Yet India remains intrinsically diffident and reactive. Without proactive diplomacy, India will continue to punch far below its weight.

Brahma Chellaney is a geostrategist and the author of nine books, including "Water: Asia's New Battleground," which won the Bernard Schwartz Award.