INCOME TAXES

Components of income tax expense related to certain of our continuing operations conducted through separate taxable wholly owned corporate subsidiaries were as follows:



	Year Ended December 31,
	2015			2014			2013
	(Thousands of Dollars)
Current:
U.S.	$	908		$	(182	)	$	3,098
Foreign	9,820			7,516			9,273
Foreign withholding tax	1,926			—			—
Total current	12,654			7,334			12,371

Deferred:
U.S.	1,022			1,889			1,687
Foreign	(1,464		)	1,578			(1,305		)
Foreign withholding tax	2,500			—			—
Total deferred	2,058			3,467			382

Total income tax expense	$	14,712		$	10,801		$	12,753

The difference between income tax expense recorded in our consolidated statements of income and income taxes computed by applying the statutory federal income tax rate (35% for all years presented) to income before income tax expense is due to the fact that the majority of our income is not subject to federal income tax due to our status as a limited partnership.

The tax effects of significant temporary differences representing deferred income tax assets and liabilities were as follows:



	December 31,
	2015			2014
	(Thousands of Dollars)
Deferred income tax assets:
Net operating losses	$	33,043		$	35,698
Environmental and legal reserves	894			664
Allowance for bad debt	2,698			1,261
Other	1,758			1,827
Total deferred income tax assets	38,393			39,450
Less: Valuation allowance	(13,151		)	(14,532		)
Net deferred income tax assets	25,242			24,918

Deferred income tax liabilities:
Property, plant and equipment	(44,880		)	(47,797		)
Foreign withholding tax	(2,314		)	—
Total deferred income tax liabilities	(47,194		)	(47,797		)

Net deferred income tax liability	$	(21,952	)	$	(22,879	)

Reported on the consolidated balance sheets as:
Deferred income tax asset	$	2,858		$	4,429
Deferred income tax liability	(24,810		)	(27,308		)
Net deferred income tax liability	$	(21,952	)	$	(22,879	)

As of December 31, 2015, our U.S. and foreign corporate operations have net operating loss carryforwards for tax purposes totaling approximately $83.3 million and $13.1 million, respectively, which are subject to various limitations on use and expire in years 2021 through 2024 for U.S. losses and in years 2016 and 2018 for foreign losses.

As of December 31, 2015 and 2014, we recorded a valuation allowance of $13.2 million and $14.5 million, respectively, related to our deferred tax assets. We estimate the amount of valuation allowance based upon our expectations of taxable income in the various jurisdictions in which we operate and the period over which we can utilize those future deductions. The valuation allowance reflects uncertainties related to our ability to utilize certain net operating loss carryforwards before they expire. In 2015, the valuation allowance decreased $1.1 million for the U.S. net operating loss and decreased $0.2 million for the foreign net operating loss, due to changes in our estimates of the amount of those loss carryforwards that will be realized, based upon future taxable income.

The realization of net deferred income tax assets recorded as of December 31, 2015 is dependent upon our ability to generate future taxable income in the United States. We believe it is more likely than not that the net deferred income tax assets as of December 31, 2015 will be realized, based on expected future taxable income.

Repatriation

Previously all undistributed earnings of our foreign subsidiaries were indefinitely reinvested. In the fourth quarter of 2015, management determined that we would begin to repatriate a portion of undistributed foreign earnings in order to provide greater flexibility to meet cash flow needs. As a result, we recognized a current tax liability of $1.9 million and a deferred tax liability of $2.5 million related to foreign withholding taxes on approximately $90.0 million of undistributed foreign earnings.

St. Eustatius Tax Agreement

On February 22, 2006, we entered into a Tax and Maritime Agreement with the governments of St. Eustatius and the Netherlands Antilles (the 2005 Tax Agreement). The 2005 Tax Agreement was effective beginning January 1, 2005 and expired on December 31, 2014. The 2005 Tax Agreement provides for annual minimum profit tax of approximately $0.6 million, beginning as of January 1, 2005.

Effective January 1, 2011, the Netherlands Antilles ceased to exist, and St. Eustatius became part of the Netherlands. The Netherlands Tax Ministry (the Ministry) contends that as of January 2011, we are subject to real estate tax rather than profit tax as expressed in our 2005 Tax Agreement. In 2013, the Ministry issued a property tax assessment for years 2011 through 2012. We objected to and appealed the assessment. The Ministry later issued property tax assessments for the years 2013 and 2014, to which we have or will file similar objections. In 2013, we filed a lawsuit in the Netherlands civil court seeking to enforce the terms of our existing 2005 Tax Agreement. In 2014, the Netherlands civil court determined that it did not have jurisdiction and deferred to the jurisdiction of the tax court; we appealed this decision. In 2015, the tax court held that NuStar was obligated to pay the property tax. In February 2016, the civil appellate court also ruled against NuStar, deferring to the decision of the tax court. We are evaluating whether to file a further appeal.