DUBAI, UNITED ARAB EMIRATES – Bahrain aims to end years of instability with a crackdown on Shiite political parties, but it could be a gamble that risks further destabilizing the Western-allied kingdom and the wider Middle East.

Five years after it crushed street protests with Saudi military support, the Sunni Muslim royal family that rules over a population with a Shiite majority appears convinced it will again be able to weather international disapproval of its tough measures.

In a series of moves over the past three weeks, authorities closed down the main Shiite opposition al-Wefaq Islamic Society, doubled the prison sentence of the group’s leader, Sheikh Ali Salman, detained prominent rights campaigner Nabeel Rajab and stripped Ayatollah Isa Qassim, Bahrain’s Shiite spiritual leader, of his citizenship.

Authorities have managed to muzzle anger each time by deploying extra police officers to the streets, but the move against Qassim this week brought thousands together in spontaneous protests outside his home west of the capital Manama.

The United States and other Western countries have expressed alarm, but Bahrain appears to be calculating that the distaste will not translate into concrete reprisals against a country closely allied to key U.S. partner Saudi Arabia.

However, opponents say that by limiting peaceful ways to express their views through a recognized group like al-Wefaq, the government will only push Shiite youths into the arms of extremists, including some responsible for bomb attacks.

“Dangerously, by outlawing the moderate opposition, the authorities are pushing all opposition into illegality, which strengthens hardliners on all sides,” said Ali Alaswad, a former member of parliament from al-Wefaq, now in exile.

“That clearly leaves the prospect for dialogue and reconciliation completely dead in the water. This will not take the country forward.”

The concern is shared even by some who support the authorities.

“Extremism is currently confined to small arenas, involving mostly young men, many of them living abroad,” said a former Bahraini official who asked not to be identified in a country where open criticism of official policy is often muted.

“When the main group (al-Wefaq) is struck, I believe that even without intending it, you are opening the arena to all kinds of extremism,” he added.

Regional analysts worry that an intensification of sectarian animosity in Bahrain could spill over into the wider region, where allies of Sunni Saudi Arabia and Shiite Iran are fighting proxy wars from Syria to Yemen.

The United States, which maintains its navy’s Middle East headquarters in Bahrain, expressed alarm at the stripping of Qassim’s citizenship.

A U.S. State Department report delivered to Congress this week said that Bahrain’s efforts to build national reconciliation have stalled and it has not implemented recommendations to protect freedom of expression, including nonviolent dissent.

In the report, the State Department says that Bahrain has made progress toward implementing reforms recommended by an independent commission, but “more work remains to be done.”

The report, which was delayed for months, appears to represent muted criticism of a strategically-located country.

Bahrain has defended its actions as necessary for national security. The authorities accuse al-Wefaq and Qassim of promoting sectarianism and of having links to Iran, which they blame for backing militants who have used improvised bombs to attack security forces, killing 17 officers since 2011, according to the interior ministry.

Iran denies fomenting violence. But the commander of an elite force in Iran’s powerful Revolutionary Guards, Qassem Soleimani, responded to the stripping of the cleric’s citizenship by suggesting Bahrainis may have no choice but to resort to “armed resistance” against the ruling Al Khalifa dynasty.

Some critics say Bahrain may have been encouraged to launch its latest crackdown by a timid response from Washington to the kingdom’s suppression of protests five years ago, when “Arab Spring” demonstrations were sweeping the region.

“This is the most naked show of brutal force since the violent 2011 crackdown,” wrote Brian Dooley of the U.S. group Human Rights First, which lobbies Washington to stress the importance of rights in its foreign policy.

“It leaves the U.S. government’s approach of quiet diplomacy and big rewards for small gestures of reform in tatters.”

After an international inquiry into the government’s handling of the 2011 unrest, Bahrain made some reforms and opened political dialogue with Shiite parties.

However, talks with the opposition ended without agreement in 2013, and since then Bahrain has remained gripped by political deadlock. More recently, the smouldering discontent on the streets has been exacerbated by financial strains caused by lower oil prices.

Bahrain’s close ally Saudi Arabia, which allows no independent political parties of its own, has been skeptical of pro-democracy measures.

Bahrain is connected by a causeway to Saudi Arabia’s oil-rich Eastern Province, home to a large Shiite minority, and Riyadh worries that its own Shiites could be emboldened by gains by Shiites in Bahrain.

Some experts attribute the crackdown to a resurgence in influence of Bahraini government hardliners who see limiting Shiite power as a natural part of Arab opposition to non-Arab Iran, and who have been emboldened since reform talks stalled.

However, others say al-Wefaq shares the blame, after it, along with three smaller opposition groups, boycotted parliamentary elections in November 2014. That made the opposition vulnerable to accusations that it was not interested in dialogue.

Al-Wefaq said it chose not to take part in the vote because the elected parliament would not have enough power and because voting districts favoured the Sunni minority.

“This is all still a fallout from the decision of al-Wefaq not to participate in the most recent parliamentary elections, and they see Ali Salman as someone who is not willing to compromise,” said Justin Gengler, a Qatar-based Bahrain expert.